Blazor API Review: UIEventArgs types

Fixes: #12550

Removes UIEventArgs in favor of EventArgs as the base class.

Moving Type into all of our event args types - this is important because
many of the events types are used for multiple events.

The only think about this that isn't perfect is that we have keep
special casing change because of how binding works. I renamed the type
to drop the `UI` prefix. It's not possible to define a subclass in the
Web project because of the way covariance works (or doesn't work) in
.NET.

src/Components/Blazor/Blazor/ref/Microsoft.AspNetCore.Blazor.netstandard2.0.cs

@@ -62,7 +62,7 @@ namespace Microsoft.AspNetCore.Blazor.Rendering
         public override Microsoft.AspNetCore.Components.Dispatcher Dispatcher { get { throw null; } }
         public System.Threading.Tasks.Task AddComponentAsync(System.Type componentType, string domElementSelector) { throw null; }
         public System.Threading.Tasks.Task AddComponentAsync<TComponent>(string domElementSelector) where TComponent : Microsoft.AspNetCore.Components.IComponent { throw null; }
-        public override System.Threading.Tasks.Task DispatchEventAsync(ulong eventHandlerId, Microsoft.AspNetCore.Components.Rendering.EventFieldInfo eventFieldInfo, Microsoft.AspNetCore.Components.UIEventArgs eventArgs) { throw null; }
+        public override System.Threading.Tasks.Task DispatchEventAsync(ulong eventHandlerId, Microsoft.AspNetCore.Components.Rendering.EventFieldInfo eventFieldInfo, System.EventArgs eventArgs) { throw null; }
         protected override void Dispose(bool disposing) { }
         protected override void HandleException(System.Exception exception) { }
         protected override System.Threading.Tasks.Task UpdateDisplayAsync(in Microsoft.AspNetCore.Components.Rendering.RenderBatch batch) { throw null; }

src/Components/Blazor/Blazor/src/Rendering/WebAssemblyRenderer.cs

@@ -120,7 +120,7 @@ namespace Microsoft.AspNetCore.Blazor.Rendering
         }
 
         /// <inheritdoc />
-        public override Task DispatchEventAsync(ulong eventHandlerId, EventFieldInfo eventFieldInfo, UIEventArgs eventArgs)
+        public override Task DispatchEventAsync(ulong eventHandlerId, EventFieldInfo eventFieldInfo, EventArgs eventArgs)
         {
             // Be sure we only run one event handler at once. Although they couldn't run
             // simultaneously anyway (there's only one thread), they could run nested on
@@ -185,10 +185,10 @@ namespace Microsoft.AspNetCore.Blazor.Rendering
         {
             public readonly ulong EventHandlerId;
             public readonly EventFieldInfo EventFieldInfo;
-            public readonly UIEventArgs EventArgs;
+            public readonly EventArgs EventArgs;
             public readonly TaskCompletionSource<object> TaskCompletionSource;
 
-            public IncomingEventInfo(ulong eventHandlerId, EventFieldInfo eventFieldInfo, UIEventArgs eventArgs)
+            public IncomingEventInfo(ulong eventHandlerId, EventFieldInfo eventFieldInfo, EventArgs eventArgs)
             {
                 EventHandlerId = eventHandlerId;
                 EventFieldInfo = eventFieldInfo;

src/Components/Blazor/Build/test/ComponentRenderingRazorIntegrationTest.cs

@@ -253,7 +253,7 @@ namespace Test
     public class MyComponent : ComponentBase
     {
         [Parameter]
-        public Action<UIEventArgs> OnClick { get; set; }
+        public Action<EventArgs> OnClick { get; set; }
     }
 }
 "));
@@ -263,7 +263,7 @@ namespace Test
 
 @code {
     private int counter;
-    private void Increment(UIEventArgs e) {
+    private void Increment(EventArgs e) {
         counter++;
     }
 }");
@@ -280,7 +280,7 @@ namespace Test
                     AssertFrame.Attribute(frame, "OnClick", 1);
 
                     // The handler will have been assigned to a lambda
-                    var handler = Assert.IsType<Action<UIEventArgs>>(frame.AttributeValue);
+                    var handler = Assert.IsType<Action<EventArgs>>(frame.AttributeValue);
                     Assert.Equal("Test.TestComponent", handler.Target.GetType().FullName);
                     Assert.Equal("Increment", handler.Method.Name);
                 });

src/Components/Blazor/Build/test/RenderingRazorIntegrationTest.cs

@@ -332,7 +332,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = "Modified value", }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = "Modified value", }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -367,7 +367,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = "Modified value", }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = "Modified value", }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -404,7 +404,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             //
             // This should always complete synchronously.
             var newDateValue = new DateTime(2018, 3, 5, 4, 5, 6);
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = newDateValue.ToString(), }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = newDateValue.ToString(), }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -440,7 +440,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = new DateTime(2018, 3, 5).ToString(testDateFormat), }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = new DateTime(2018, 3, 5).ToString(testDateFormat), }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -559,7 +559,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task =  renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs() { Value = false, }));
+            var task =  renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs() { Value = false, }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -595,7 +595,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = MyEnum.SecondValue.ToString(), }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = MyEnum.SecondValue.ToString(), }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 

src/Components/Components/ref/Microsoft.AspNetCore.Components.netstandard2.0.cs

@@ -119,6 +119,11 @@ namespace Microsoft.AspNetCore.Components
         public void Attach(Microsoft.AspNetCore.Components.RenderHandle renderHandle) { }
         public System.Threading.Tasks.Task SetParametersAsync(Microsoft.AspNetCore.Components.ParameterView parameters) { throw null; }
     }
+    public partial class ChangeEventArgs : System.EventArgs
+    {
+        public ChangeEventArgs() { }
+        public object Value { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
+    }
     public abstract partial class ComponentBase : Microsoft.AspNetCore.Components.IComponent, Microsoft.AspNetCore.Components.IHandleAfterRender, Microsoft.AspNetCore.Components.IHandleEvent
     {
         public ComponentBase() { }
@@ -188,35 +193,35 @@ namespace Microsoft.AspNetCore.Components
     }
     public static partial class EventCallbackFactoryBinderExtensions
     {
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<bool> setter, bool existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<bool> setter, bool existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTimeOffset> setter, System.DateTimeOffset existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTimeOffset> setter, System.DateTimeOffset existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTimeOffset> setter, System.DateTimeOffset existingValue, string format, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTimeOffset> setter, System.DateTimeOffset existingValue, string format, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTime> setter, System.DateTime existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTime> setter, System.DateTime existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTime> setter, System.DateTime existingValue, string format, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTime> setter, System.DateTime existingValue, string format, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<decimal> setter, decimal existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<decimal> setter, decimal existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<double> setter, double existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<double> setter, double existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<int> setter, int existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<int> setter, int existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<long> setter, long existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<long> setter, long existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<bool?> setter, bool? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<bool?> setter, bool? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTimeOffset?> setter, System.DateTimeOffset? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTimeOffset?> setter, System.DateTimeOffset? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTimeOffset?> setter, System.DateTimeOffset? existingValue, string format, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTimeOffset?> setter, System.DateTimeOffset? existingValue, string format, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTime?> setter, System.DateTime? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTime?> setter, System.DateTime? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTime?> setter, System.DateTime? existingValue, string format, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.DateTime?> setter, System.DateTime? existingValue, string format, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<decimal?> setter, decimal? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<decimal?> setter, decimal? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<double?> setter, double? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<double?> setter, double? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<int?> setter, int? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<int?> setter, int? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<long?> setter, long? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<long?> setter, long? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<float?> setter, float? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<float?> setter, float? existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<float> setter, float existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<float> setter, float existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<string> setter, string existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<string> setter, string existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> CreateBinder<T>(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<T> setter, T existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> CreateBinder<T>(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<T> setter, T existingValue, System.Globalization.CultureInfo culture = null) { throw null; }
     }
-    public static partial class EventCallbackFactoryUIEventArgsExtensions
+    public static partial class EventCallbackFactoryEventArgsExtensions
     {
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> Create(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<Microsoft.AspNetCore.Components.UIChangeEventArgs> callback) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> Create(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<Microsoft.AspNetCore.Components.ChangeEventArgs> callback) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIEventArgs> Create(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<Microsoft.AspNetCore.Components.UIEventArgs> callback) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<System.EventArgs> Create(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Action<System.EventArgs> callback) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIChangeEventArgs> Create(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Func<Microsoft.AspNetCore.Components.UIChangeEventArgs, System.Threading.Tasks.Task> callback) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.ChangeEventArgs> Create(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Func<Microsoft.AspNetCore.Components.ChangeEventArgs, System.Threading.Tasks.Task> callback) { throw null; }
-        public static Microsoft.AspNetCore.Components.EventCallback<Microsoft.AspNetCore.Components.UIEventArgs> Create(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Func<Microsoft.AspNetCore.Components.UIEventArgs, System.Threading.Tasks.Task> callback) { throw null; }
+        public static Microsoft.AspNetCore.Components.EventCallback<System.EventArgs> Create(this Microsoft.AspNetCore.Components.EventCallbackFactory factory, object receiver, System.Func<System.EventArgs, System.Threading.Tasks.Task> callback) { throw null; }
     }
     [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
     public readonly partial struct EventCallbackWorkItem
@@ -365,16 +370,6 @@ namespace Microsoft.AspNetCore.Components
         public RouteAttribute(string template) { }
         public string Template { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
     }
-    public partial class UIChangeEventArgs : Microsoft.AspNetCore.Components.UIEventArgs
-    {
-        public UIChangeEventArgs() { }
-        public object Value { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
-    }
-    public partial class UIEventArgs
-    {
-        public UIEventArgs() { }
-        public string Type { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
-    }
     public abstract partial class UriHelperBase : Microsoft.AspNetCore.Components.IUriHelper
     {
         protected UriHelperBase() { }
@@ -516,7 +511,7 @@ namespace Microsoft.AspNetCore.Components.Rendering
         public event System.UnhandledExceptionEventHandler UnhandledSynchronizationException { add { } remove { } }
         protected internal virtual void AddToRenderQueue(int componentId, Microsoft.AspNetCore.Components.RenderFragment renderFragment) { }
         protected internal int AssignRootComponentId(Microsoft.AspNetCore.Components.IComponent component) { throw null; }
-        public virtual System.Threading.Tasks.Task DispatchEventAsync(ulong eventHandlerId, Microsoft.AspNetCore.Components.Rendering.EventFieldInfo fieldInfo, Microsoft.AspNetCore.Components.UIEventArgs eventArgs) { throw null; }
+        public virtual System.Threading.Tasks.Task DispatchEventAsync(ulong eventHandlerId, Microsoft.AspNetCore.Components.Rendering.EventFieldInfo fieldInfo, System.EventArgs eventArgs) { throw null; }
         public void Dispose() { }
         protected virtual void Dispose(bool disposing) { }
         protected abstract void HandleException(System.Exception exception);

src/Components/Components/src/ChangeEventArgs.cs

@@ -1,16 +1,19 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
-    /// Supplies information about an event that is being raised.
+    /// Supplies information about an change event that is being raised.
     /// </summary>
-    public class UIEventArgs
+    public class ChangeEventArgs : EventArgs
     {
         /// <summary>
-        /// Gets or sets the type of the event.
+        /// Gets or sets the new value.
         /// </summary>
-        public string Type { get; set; }
+        public object Value { get; set; }
+
     }
 }

src/Components/Components/src/EventCallbackFactoryBinderExtensions.cs

@@ -31,7 +31,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<string> setter,
@@ -50,7 +50,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<bool> setter,
@@ -69,7 +69,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<bool?> setter,
@@ -88,7 +88,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<int> setter,
@@ -107,7 +107,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<int?> setter,
@@ -126,7 +126,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<long> setter,
@@ -145,7 +145,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<long?> setter,
@@ -164,7 +164,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<float> setter,
@@ -183,7 +183,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<float?> setter,
@@ -202,7 +202,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<double> setter,
@@ -221,7 +221,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<double?> setter,
@@ -240,7 +240,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<decimal> setter,
@@ -259,7 +259,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<decimal?> setter,
@@ -278,7 +278,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<DateTime> setter,
@@ -298,7 +298,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="format"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<DateTime> setter,
@@ -318,7 +318,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<DateTime?> setter,
@@ -338,7 +338,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="format"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<DateTime?> setter,
@@ -358,7 +358,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<DateTimeOffset> setter,
@@ -378,7 +378,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="format"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<DateTimeOffset> setter,
@@ -398,7 +398,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<DateTimeOffset?> setter,
@@ -418,7 +418,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="format"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder(
+        public static EventCallback<ChangeEventArgs> CreateBinder(
             this EventCallbackFactory factory,
             object receiver,
             Action<DateTimeOffset?> setter,
@@ -439,7 +439,7 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="existingValue"></param>
         /// <param name="culture"></param>
         /// <returns></returns>
-        public static EventCallback<UIChangeEventArgs> CreateBinder<T>(
+        public static EventCallback<ChangeEventArgs> CreateBinder<T>(
             this EventCallbackFactory factory,
             object receiver,
             Action<T> setter,
@@ -449,14 +449,14 @@ namespace Microsoft.AspNetCore.Components
             return CreateBinderCore<T>(factory, receiver, setter, culture, ParserDelegateCache.Get<T>());
         }
 
-        private static EventCallback<UIChangeEventArgs> CreateBinderCore<T>(
+        private static EventCallback<ChangeEventArgs> CreateBinderCore<T>(
             this EventCallbackFactory factory,
             object receiver,
             Action<T> setter,
             CultureInfo culture,
             BindConverter.BindParser<T> converter)
         {
-            Action<UIChangeEventArgs> callback = e =>
+            Action<ChangeEventArgs> callback = e =>
             {
                 T value = default;
                 var converted = false;
@@ -489,10 +489,10 @@ namespace Microsoft.AspNetCore.Components
                     setter(default);
                 }
             };
-            return factory.Create<UIChangeEventArgs>(receiver, callback);
+            return factory.Create<ChangeEventArgs>(receiver, callback);
         }
 
-        private static EventCallback<UIChangeEventArgs> CreateBinderCore<T>(
+        private static EventCallback<ChangeEventArgs> CreateBinderCore<T>(
             this EventCallbackFactory factory,
             object receiver,
             Action<T> setter,
@@ -500,7 +500,7 @@ namespace Microsoft.AspNetCore.Components
             string format,
             BindConverter.BindParserWithFormat<T> converter)
         {
-            Action<UIChangeEventArgs> callback = e =>
+            Action<ChangeEventArgs> callback = e =>
             {
                 T value = default;
                 var converted = false;
@@ -533,7 +533,7 @@ namespace Microsoft.AspNetCore.Components
                     setter(default);
                 }
             };
-            return factory.Create<UIChangeEventArgs>(receiver, callback);
+            return factory.Create<ChangeEventArgs>(receiver, callback);
         }
     }
 }

src/Components/Components/src/EventCallbackFactoryEventArgsExtensions.cs

@@ -7,9 +7,9 @@ using System.Threading.Tasks;
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
-    /// Provides extension methods for <see cref="EventCallbackFactory"/> and <see cref="UIEventArgs"/> types.
+    /// Provides extension methods for <see cref="EventCallbackFactory"/> and <see cref="EventArgs"/> types.
     /// </summary>
-    public static class EventCallbackFactoryUIEventArgsExtensions
+    public static class EventCallbackFactoryEventArgsExtensions
     {
         /// <summary>
         /// Creates an <see cref="EventCallback"/> for the provided <paramref name="receiver"/> and
@@ -19,14 +19,14 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="receiver">The event receiver.</param>
         /// <param name="callback">The event callback.</param>
         /// <returns>The <see cref="EventCallback"/>.</returns>
-        public static EventCallback<UIEventArgs> Create(this EventCallbackFactory factory, object receiver, Action<UIEventArgs> callback)
+        public static EventCallback<EventArgs> Create(this EventCallbackFactory factory, object receiver, Action<EventArgs> callback)
         {
             if (factory == null)
             {
                 throw new ArgumentNullException(nameof(factory));
             }
 
-            return factory.Create<UIEventArgs>(receiver, callback);
+            return factory.Create<EventArgs>(receiver, callback);
         }
 
         /// <summary>
@@ -37,14 +37,14 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="receiver">The event receiver.</param>
         /// <param name="callback">The event callback.</param>
         /// <returns>The <see cref="EventCallback"/>.</returns>
-        public static EventCallback<UIEventArgs> Create(this EventCallbackFactory factory, object receiver, Func<UIEventArgs, Task> callback)
+        public static EventCallback<EventArgs> Create(this EventCallbackFactory factory, object receiver, Func<EventArgs, Task> callback)
         {
             if (factory == null)
             {
                 throw new ArgumentNullException(nameof(factory));
             }
 
-            return factory.Create<UIEventArgs>(receiver, callback);
+            return factory.Create<EventArgs>(receiver, callback);
         }
 
         /// <summary>
@@ -55,14 +55,14 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="receiver">The event receiver.</param>
         /// <param name="callback">The event callback.</param>
         /// <returns>The <see cref="EventCallback"/>.</returns>
-        public static EventCallback<UIChangeEventArgs> Create(this EventCallbackFactory factory, object receiver, Action<UIChangeEventArgs> callback)
+        public static EventCallback<ChangeEventArgs> Create(this EventCallbackFactory factory, object receiver, Action<ChangeEventArgs> callback)
         {
             if (factory == null)
             {
                 throw new ArgumentNullException(nameof(factory));
             }
 
-            return factory.Create<UIChangeEventArgs>(receiver, callback);
+            return factory.Create<ChangeEventArgs>(receiver, callback);
         }
 
         /// <summary>
@@ -73,14 +73,14 @@ namespace Microsoft.AspNetCore.Components
         /// <param name="receiver">The event receiver.</param>
         /// <param name="callback">The event callback.</param>
         /// <returns>The <see cref="EventCallback"/>.</returns>
-        public static EventCallback<UIChangeEventArgs> Create(this EventCallbackFactory factory, object receiver, Func<UIChangeEventArgs, Task> callback)
+        public static EventCallback<ChangeEventArgs> Create(this EventCallbackFactory factory, object receiver, Func<ChangeEventArgs, Task> callback)
         {
             if (factory == null)
             {
                 throw new ArgumentNullException(nameof(factory));
             }
 
-            return factory.Create<UIChangeEventArgs>(receiver, callback);
+            return factory.Create<ChangeEventArgs>(receiver, callback);
         }
     }
 }

src/Components/Components/src/Rendering/Renderer.Log.cs

@@ -56,9 +56,9 @@ namespace Microsoft.AspNetCore.Components.Rendering
                 }
             }
 
-            internal static void HandlingEvent(ILogger<Renderer> logger, ulong eventHandlerId, UIEventArgs eventArgs)
+            internal static void HandlingEvent(ILogger<Renderer> logger, ulong eventHandlerId, EventArgs eventArgs)
             {
-                _handlingEvent(logger, eventHandlerId, eventArgs?.Type ?? "null", null);
+                _handlingEvent(logger, eventHandlerId, eventArgs?.GetType().Name ?? "null", null);
             }
         }
     }

src/Components/Components/src/Rendering/Renderer.cs

@@ -206,7 +206,7 @@ namespace Microsoft.AspNetCore.Components.Rendering
         /// A <see cref="Task"/> which will complete once all asynchronous processing related to the event
         /// has completed.
         /// </returns>
-        public virtual Task DispatchEventAsync(ulong eventHandlerId, EventFieldInfo fieldInfo, UIEventArgs eventArgs)
+        public virtual Task DispatchEventAsync(ulong eventHandlerId, EventFieldInfo fieldInfo, EventArgs eventArgs)
         {
             EnsureSynchronizationContext();
 

src/Components/Components/src/UIChangeEventArgs.cs

@@ -1,17 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-namespace Microsoft.AspNetCore.Components
-{
-    /// <summary>
-    /// Supplies information about an input change event that is being raised.
-    /// </summary>
-    public class UIChangeEventArgs : UIEventArgs
-    {
-        /// <summary>
-        /// Gets or sets the new value of the input. This may be a <see cref="string"/>
-        /// or a <see cref="bool"/>.
-        /// </summary>
-        public object Value { get; set; }
-    }
-}

src/Components/Components/test/EventCallbackFactoryBinderExtensionsTest.cs

@@ -23,7 +23,7 @@ namespace Microsoft.AspNetCore.Components
             var binder = EventCallback.Factory.CreateBinder(component, setter, value);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "not-an-integer!", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "not-an-integer!", });
 
             Assert.Equal(17, value); // Setter not called
             Assert.Equal(1, component.Count);
@@ -40,7 +40,7 @@ namespace Microsoft.AspNetCore.Components
             var binder = EventCallback.Factory.CreateBinder(component, setter, value);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = string.Empty, });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = string.Empty, });
 
             Assert.Equal(0, value); // Calls setter to apply default value for this type
             Assert.Equal(1, component.Count);
@@ -58,7 +58,7 @@ namespace Microsoft.AspNetCore.Components
             // Act
             await Assert.ThrowsAsync<InvalidTimeZoneException>(() =>
             {
-                return binder.InvokeAsync(new UIChangeEventArgs() { Value = "18", });
+                return binder.InvokeAsync(new ChangeEventArgs() { Value = "18", });
             });
 
             Assert.Equal(1, component.Count);
@@ -75,7 +75,7 @@ namespace Microsoft.AspNetCore.Components
             var binder = EventCallback.Factory.CreateBinder(component, setter, value);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "not-an-integer!", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "not-an-integer!", });
 
             Assert.Equal(17, value); // Setter not called
             Assert.Equal(1, component.Count);
@@ -92,7 +92,7 @@ namespace Microsoft.AspNetCore.Components
             var binder = EventCallback.Factory.CreateBinder(component, setter, value);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "", });
 
             Assert.Null(value); // Setter called
             Assert.Equal(1, component.Count);
@@ -111,7 +111,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = "bye";
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue, });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue, });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -130,7 +130,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = true;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = true, });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = true, });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -149,7 +149,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (bool?)true;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = true, });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = true, });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -168,7 +168,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = 42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -187,7 +187,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (int?)42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -206,7 +206,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (long)42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -225,7 +225,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (long?)42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -244,7 +244,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (float)42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -263,7 +263,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (float?)42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -282,7 +282,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (double)42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -301,7 +301,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (double?)42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -320,7 +320,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (decimal)42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -339,7 +339,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = (decimal?)42;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -358,7 +358,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = AttributeTargets.Class;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -377,7 +377,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = AttributeTargets.Class;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -396,7 +396,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = new DateTime(2018, 3, 4, 1, 2, 3);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -415,7 +415,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = new DateTime(2018, 3, 4, 1, 2, 3);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -435,7 +435,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = new DateTime(2018, 3, 4);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(format), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(format), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -455,7 +455,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = new DateTime(2018, 3, 4);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(format), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(format), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -474,7 +474,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = new DateTime(2018, 3, 4, 1, 2, 3);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -493,7 +493,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = new DateTime(2018, 3, 4, 1, 2, 3);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -513,7 +513,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = new DateTime(2018, 3, 4);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(format), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(format), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -533,7 +533,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = new DateTime(2018, 3, 4);
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(format), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(format), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -553,7 +553,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = Guid.NewGuid();
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -573,7 +573,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = Guid.NewGuid();
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(), });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -592,7 +592,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = new SecretMessage() { Message = "TypeConverter may be old, but it still works!", };
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = expectedValue.ToString(), });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = expectedValue.ToString(), });
 
             Assert.Equal(expectedValue.Message, value.Message);
             Assert.Equal(1, component.Count);
@@ -627,7 +627,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = 42_000;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42 000,00", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42 000,00", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);
@@ -646,7 +646,7 @@ namespace Microsoft.AspNetCore.Components
             var expectedValue = 42_000;
 
             // Act
-            await binder.InvokeAsync(new UIChangeEventArgs() { Value = "42,000.00", });
+            await binder.InvokeAsync(new ChangeEventArgs() { Value = "42,000.00", });
 
             Assert.Equal(expectedValue, value);
             Assert.Equal(1, component.Count);

src/Components/Components/test/EventCallbackTest.cs

@@ -24,7 +24,7 @@ namespace Microsoft.AspNetCore.Components
         public async Task EventCallbackOfT_Default()
         {
             // Arrange
-            var callback = default(EventCallback<UIEventArgs>);
+            var callback = default(EventCallback<EventArgs>);
 
             // Act & Assert (Does not throw)
             await callback.InvokeAsync(null);
@@ -51,7 +51,7 @@ namespace Microsoft.AspNetCore.Components
         {
             // Arrange
             int runCount = 0;
-            var callback = new EventCallback<UIEventArgs>(null, (Action)(() => runCount++));
+            var callback = new EventCallback<EventArgs>(null, (Action)(() => runCount++));
 
             // Act
             await callback.InvokeAsync(null);
@@ -89,7 +89,7 @@ namespace Microsoft.AspNetCore.Components
             var callback = new EventCallback(component, (Action)(() => runCount++));
 
             // Act
-            await callback.InvokeAsync(new UIEventArgs());
+            await callback.InvokeAsync(new EventArgs());
 
 
             // Assert
@@ -104,8 +104,8 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback(component, (Action<UIEventArgs>)((e) => { arg = e; runCount++; }));
+            var callback = new EventCallback(component, (Action<EventArgs>)((e) => { arg = e; runCount++; }));
 
             // Act
             await callback.InvokeAsync(null);
@@ -124,11 +124,11 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback(component, (Action<UIEventArgs>)((e) => { arg = e; runCount++; }));
+            var callback = new EventCallback(component, (Action<EventArgs>)((e) => { arg = e; runCount++; }));
 
             // Act
-            await callback.InvokeAsync(new UIEventArgs());
+            await callback.InvokeAsync(new EventArgs());
 
 
             // Assert
@@ -164,8 +164,8 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback(component, (Action<UIEventArgs>)((e) => { arg = e; runCount++; }));
+            var callback = new EventCallback(component, (Action<EventArgs>)((e) => { arg = e; runCount++; }));
 
             // Act & Assert
             await Assert.ThrowsAsync<ArgumentException>(() =>
@@ -202,7 +202,7 @@ namespace Microsoft.AspNetCore.Components
             var callback = new EventCallback(component, (Func<Task>)(() => { runCount++; return Task.CompletedTask; }));
 
             // Act
-            await callback.InvokeAsync(new UIEventArgs());
+            await callback.InvokeAsync(new EventArgs());
 
 
             // Assert
@@ -217,8 +217,8 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback(component, (Func<UIEventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
+            var callback = new EventCallback(component, (Func<EventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
 
             // Act
             await callback.InvokeAsync(null);
@@ -237,11 +237,11 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback(component, (Func<UIEventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
+            var callback = new EventCallback(component, (Func<EventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
 
             // Act
-            await callback.InvokeAsync(new UIEventArgs());
+            await callback.InvokeAsync(new EventArgs());
 
 
             // Assert
@@ -277,8 +277,8 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback(component, (Func<UIEventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
+            var callback = new EventCallback(component, (Func<EventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
 
             // Act & Assert
             await Assert.ThrowsAsync<ArgumentException>(() =>
@@ -294,7 +294,7 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            var callback = new EventCallback<UIEventArgs>(component, (Action)(() => runCount++));
+            var callback = new EventCallback<EventArgs>(component, (Action)(() => runCount++));
 
             // Act
             await callback.InvokeAsync(null);
@@ -312,10 +312,10 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            var callback = new EventCallback<UIEventArgs>(component, (Action)(() => runCount++));
+            var callback = new EventCallback<EventArgs>(component, (Action)(() => runCount++));
 
             // Act
-            await callback.InvokeAsync(new UIEventArgs());
+            await callback.InvokeAsync(new EventArgs());
 
 
             // Assert
@@ -330,8 +330,8 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback<UIEventArgs>(component, (Action<UIEventArgs>)((e) => { arg = e; runCount++; }));
+            var callback = new EventCallback<EventArgs>(component, (Action<EventArgs>)((e) => { arg = e; runCount++; }));
 
             // Act
             await callback.InvokeAsync(null);
@@ -350,11 +350,11 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback<UIEventArgs>(component, (Action<UIEventArgs>)((e) => { arg = e; runCount++; }));
+            var callback = new EventCallback<EventArgs>(component, (Action<EventArgs>)((e) => { arg = e; runCount++; }));
 
             // Act
-            await callback.InvokeAsync(new UIEventArgs());
+            await callback.InvokeAsync(new EventArgs());
 
 
             // Assert
@@ -370,7 +370,7 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            var callback = new EventCallback<UIEventArgs>(component, (Func<Task>)(() => { runCount++; return Task.CompletedTask; }));
+            var callback = new EventCallback<EventArgs>(component, (Func<Task>)(() => { runCount++; return Task.CompletedTask; }));
 
             // Act
             await callback.InvokeAsync(null);
@@ -388,10 +388,10 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            var callback = new EventCallback<UIEventArgs>(component, (Func<Task>)(() => { runCount++; return Task.CompletedTask; }));
+            var callback = new EventCallback<EventArgs>(component, (Func<Task>)(() => { runCount++; return Task.CompletedTask; }));
 
             // Act
-            await callback.InvokeAsync(new UIEventArgs());
+            await callback.InvokeAsync(new EventArgs());
 
 
             // Assert
@@ -406,8 +406,8 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback<UIEventArgs>(component, (Func<UIEventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
+            var callback = new EventCallback<EventArgs>(component, (Func<EventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
 
             // Act
             await callback.InvokeAsync(null);
@@ -426,11 +426,11 @@ namespace Microsoft.AspNetCore.Components
             var component = new EventCountingComponent();
 
             int runCount = 0;
-            UIEventArgs arg = null;
+            EventArgs arg = null;
-            var callback = new EventCallback<UIEventArgs>(component, (Func<UIEventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
+            var callback = new EventCallback<EventArgs>(component, (Func<EventArgs, Task>)((e) => { arg = e; runCount++; return Task.CompletedTask; }));
 
             // Act
-            await callback.InvokeAsync(new UIEventArgs());
+            await callback.InvokeAsync(new EventArgs());
 
 
             // Assert

src/Components/Components/test/RenderTreeBuilderTest.cs

@@ -216,7 +216,7 @@ namespace Microsoft.AspNetCore.Components.Test
         {
             // Arrange
             var builder = new RenderTreeBuilder();
-            Action<UIEventArgs> eventHandler = eventInfo => { };
+            Action<EventArgs> eventHandler = eventInfo => { };
 
             // Act
             builder.OpenElement(0, "myelement");                    //  0: <myelement
@@ -261,7 +261,7 @@ namespace Microsoft.AspNetCore.Components.Test
         {
             // Arrange
             var builder = new RenderTreeBuilder();
-            Action<UIEventArgs> eventHandler = eventInfo => { };
+            Action<EventArgs> eventHandler = eventInfo => { };
 
             // Act
             builder.OpenElement(0, "myelement");
@@ -428,7 +428,7 @@ namespace Microsoft.AspNetCore.Components.Test
             {
                 builder.OpenElement(0, "some element");
                 builder.AddContent(1, "hello");
-                builder.AddAttribute(2, "name", new Action<UIEventArgs>(eventInfo => { }));
+                builder.AddAttribute(2, "name", new Action<EventArgs>(eventInfo => { }));
             });
         }
 
@@ -897,7 +897,7 @@ namespace Microsoft.AspNetCore.Components.Test
             // Arrange
             var builder = new RenderTreeBuilder();
 
-            var value = new Action<UIEventArgs>((e) => { });
+            var value = new Action<EventArgs>((e) => { });
 
             // Act
             builder.OpenElement(0, "elem");
@@ -919,7 +919,7 @@ namespace Microsoft.AspNetCore.Components.Test
 
             // Act
             builder.OpenElement(0, "elem");
-            builder.AddAttribute(1, "attr", (Action<UIEventArgs>)null);
+            builder.AddAttribute(1, "attr", (Action<EventArgs>)null);
             builder.CloseElement();
 
             // Assert
@@ -965,7 +965,7 @@ namespace Microsoft.AspNetCore.Components.Test
                 frame => AssertFrame.Element(frame, "elem", 1, 0));
         }
 
-        public static TheoryData<Action<UIEventArgs>> EventHandlerValues => new TheoryData<Action<UIEventArgs>>
+        public static TheoryData<Action<EventArgs>> EventHandlerValues => new TheoryData<Action<EventArgs>>
         {
             null,
             (e) => { },
@@ -973,7 +973,7 @@ namespace Microsoft.AspNetCore.Components.Test
 
         [Theory]
         [MemberData(nameof(EventHandlerValues))]
-        public void AddAttribute_Component_EventHandlerValue_SetsAttributeValue(Action<UIEventArgs> value)
+        public void AddAttribute_Component_EventHandlerValue_SetsAttributeValue(Action<EventArgs> value)
         {
             // Arrange
             var builder = new RenderTreeBuilder();
@@ -1241,7 +1241,7 @@ namespace Microsoft.AspNetCore.Components.Test
             // Arrange
             var builder = new RenderTreeBuilder();
 
-            var value = new Action<UIEventArgs>((e) => { });
+            var value = new Action<EventArgs>((e) => { });
 
             // Act
             builder.OpenElement(0, "elem");
@@ -1261,7 +1261,7 @@ namespace Microsoft.AspNetCore.Components.Test
             // Arrange
             var builder = new RenderTreeBuilder();
 
-            var value = new Action<UIEventArgs>((e) => { });
+            var value = new Action<EventArgs>((e) => { });
 
             // Act
             builder.OpenComponent<TestComponent>(0);

src/Components/Components/test/RenderTreeDiffBuilderTest.cs

@@ -835,9 +835,9 @@ namespace Microsoft.AspNetCore.Components.Test
         public void RecognizesAttributeEventHandlerValuesChanged()
         {
             // Arrange
-            Action<UIEventArgs> retainedHandler = _ => { };
+            Action<EventArgs> retainedHandler = _ => { };
-            Action<UIEventArgs> removedHandler = _ => { };
+            Action<EventArgs> removedHandler = _ => { };
-            Action<UIEventArgs> addedHandler = _ => { };
+            Action<EventArgs> addedHandler = _ => { };
             oldTree.OpenElement(0, "My element");
             oldTree.AddAttribute(1, "onfoo", retainedHandler);
             oldTree.AddAttribute(2, "onbar", removedHandler);
@@ -1575,7 +1575,7 @@ namespace Microsoft.AspNetCore.Components.Test
         public void PreservesEventHandlerIdsForRetainedEventHandlers()
         {
             // Arrange
-            Action<UIEventArgs> retainedHandler = _ => { };
+            Action<EventArgs> retainedHandler = _ => { };
             oldTree.OpenElement(0, "My element");
             oldTree.AddAttribute(1, "ontest", retainedHandler);
             oldTree.CloseElement();
@@ -1601,7 +1601,7 @@ namespace Microsoft.AspNetCore.Components.Test
         public void PreservesEventHandlerIdsForRetainedEventHandlers_SlowPath()
         {
             // Arrange
-            Action<UIEventArgs> retainedHandler = _ => { };
+            Action<EventArgs> retainedHandler = _ => { };
             oldTree.OpenElement(0, "My element");
             oldTree.AddAttribute(0, "ontest", retainedHandler);
             oldTree.CloseElement();

src/Components/Components/test/RendererTest.cs

@@ -430,7 +430,7 @@ namespace Microsoft.AspNetCore.Components.Test
         {
             // Arrange: Render a component with an event handler
             var renderer = new TestRenderer();
-            UIEventArgs receivedArgs = null;
+            EventArgs receivedArgs = null;
 
             var component = new EventComponent
             {
@@ -448,7 +448,7 @@ namespace Microsoft.AspNetCore.Components.Test
             Assert.Null(receivedArgs);
 
             // Act/Assert: Event can be fired
-            var eventArgs = new UIEventArgs();
+            var eventArgs = new EventArgs();
             var task = renderer.DispatchEventAsync(eventHandlerId, eventArgs);
 
             // This should always be run synchronously
@@ -460,7 +460,7 @@ namespace Microsoft.AspNetCore.Components.Test
         {
             // Arrange: Render a component with an event handler
             var renderer = new TestRenderer();
-            UIEventArgs receivedArgs = null;
+            EventArgs receivedArgs = null;
 
             var component = new EventComponent
             {
@@ -478,7 +478,7 @@ namespace Microsoft.AspNetCore.Components.Test
             Assert.Null(receivedArgs);
 
             // Act/Assert: Event can be fired
-            var eventArgs = new UIEventArgs();
+            var eventArgs = new EventArgs();
             var renderTask = renderer.DispatchEventAsync(eventHandlerId, eventArgs);
             Assert.True(renderTask.IsCompletedSuccessfully);
             Assert.Same(eventArgs, receivedArgs);
@@ -508,7 +508,7 @@ namespace Microsoft.AspNetCore.Components.Test
             Assert.Empty(renderer.HandledExceptions);
 
             // Act/Assert: Event can be fired
-            var eventArgs = new UIEventArgs();
+            var eventArgs = new EventArgs();
             var renderTask = renderer.DispatchEventAsync(eventHandlerId, eventArgs);
             Assert.True(renderTask.IsCompletedSuccessfully);
 
@@ -577,7 +577,7 @@ namespace Microsoft.AspNetCore.Components.Test
         [Fact]
         public void CanDispatchEventsToNestedComponents()
         {
-            UIEventArgs receivedArgs = null;
+            EventArgs receivedArgs = null;
 
             // Arrange: Render parent component
             var renderer = new TestRenderer();
@@ -608,7 +608,7 @@ namespace Microsoft.AspNetCore.Components.Test
             Assert.Null(receivedArgs);
 
             // Act/Assert: Event can be fired
-            var eventArgs = new UIEventArgs();
+            var eventArgs = new EventArgs();
             var renderTask = renderer.DispatchEventAsync(eventHandlerId, eventArgs);
             Assert.True(renderTask.IsCompletedSuccessfully);
             Assert.Same(eventArgs, receivedArgs);
@@ -619,7 +619,7 @@ namespace Microsoft.AspNetCore.Components.Test
         {
             // Arrange: Render a component with an event handler
             var renderer = new TestRenderer();
-            UIEventArgs receivedArgs = null;
+            EventArgs receivedArgs = null;
 
             var state = 0;
             var tcs = new TaskCompletionSource<object>();
@@ -646,7 +646,7 @@ namespace Microsoft.AspNetCore.Components.Test
             Assert.Null(receivedArgs);
 
             // Act/Assert: Event can be fired
-            var eventArgs = new UIEventArgs();
+            var eventArgs = new EventArgs();
             var task = renderer.DispatchEventAsync(eventHandlerId, eventArgs);
             Assert.Equal(1, state);
             Assert.Same(eventArgs, receivedArgs);
@@ -746,7 +746,7 @@ namespace Microsoft.AspNetCore.Components.Test
         [Fact]
         public async Task CanAsyncDispatchEventsToNestedComponents()
         {
-            UIEventArgs receivedArgs = null;
+            EventArgs receivedArgs = null;
 
             var state = 0;
             var tcs = new TaskCompletionSource<object>();
@@ -786,7 +786,7 @@ namespace Microsoft.AspNetCore.Components.Test
             Assert.Null(receivedArgs);
 
             // Act/Assert: Event can be fired
-            var eventArgs = new UIEventArgs();
+            var eventArgs = new EventArgs();
             var task = renderer.DispatchEventAsync(eventHandlerId, eventArgs);
             Assert.Equal(1, state);
             Assert.Same(eventArgs, receivedArgs);
@@ -1774,7 +1774,7 @@ namespace Microsoft.AspNetCore.Components.Test
             // Act/Assert
             await Assert.ThrowsAsync<ArgumentException>(() =>
             {
-                return renderer.DispatchEventAsync(0, new UIEventArgs());
+                return renderer.DispatchEventAsync(0, new EventArgs());
             });
         }
 
@@ -2052,7 +2052,7 @@ namespace Microsoft.AspNetCore.Components.Test
             // Arrange
             var renderer = new TestRenderer();
             var eventCount = 0;
-            Action<UIEventArgs> origEventHandler = args => { eventCount++; };
+            Action<EventArgs> origEventHandler = args => { eventCount++; };
             var component = new EventComponent { OnTest = origEventHandler };
             var componentId = renderer.AssignRootComponentId(component);
             component.TriggerRender();
@@ -2094,7 +2094,7 @@ namespace Microsoft.AspNetCore.Components.Test
             // Arrange
             var renderer = new TestRenderer();
             var eventCount = 0;
-            Action<UIEventArgs> origEventHandler = args => { eventCount++; };
+            Action<EventArgs> origEventHandler = args => { eventCount++; };
             var component = new EventComponent { OnTest = origEventHandler };
             var componentId = renderer.AssignRootComponentId(component);
             component.TriggerRender();
@@ -2129,7 +2129,7 @@ namespace Microsoft.AspNetCore.Components.Test
             // Arrange
             var renderer = new TestRenderer();
             var eventCount = 0;
-            Action<UIEventArgs> origEventHandler = args => { eventCount++; };
+            Action<EventArgs> origEventHandler = args => { eventCount++; };
             var component = new ConditionalParentComponent<EventComponent>
             {
                 IncludeChild = true,
@@ -2180,7 +2180,7 @@ namespace Microsoft.AspNetCore.Components.Test
             // Arrange
             var renderer = new TestRenderer();
             var eventCount = 0;
-            Action<UIEventArgs> origEventHandler = args => { eventCount++; };
+            Action<EventArgs> origEventHandler = args => { eventCount++; };
             var component = new EventComponent { OnTest = origEventHandler };
             var componentId = renderer.AssignRootComponentId(component);
             component.TriggerRender();
@@ -2222,7 +2222,7 @@ namespace Microsoft.AspNetCore.Components.Test
             {
                 builder.AddContent(0, "Child event count: " + eventCount);
                 builder.OpenComponent<EventComponent>(1);
-                builder.AddAttribute(2, nameof(EventComponent.OnTest), new Action<UIEventArgs>(args =>
+                builder.AddAttribute(2, nameof(EventComponent.OnTest), new Action<EventArgs>(args =>
                 {
                     eventCount++;
                     rootComponent.TriggerRender();
@@ -2468,7 +2468,7 @@ namespace Microsoft.AspNetCore.Components.Test
                 .AttributeEventHandlerId;
 
             // Act: Toggle the checkbox
-            var eventArgs = new UIChangeEventArgs { Value = true };
+            var eventArgs = new ChangeEventArgs { Value = true };
             var renderTask =  renderer.DispatchEventAsync(checkboxChangeEventHandlerId, eventArgs);
 
             Assert.True(renderTask.IsCompletedSuccessfully);
@@ -2713,7 +2713,7 @@ namespace Microsoft.AspNetCore.Components.Test
             };
             var numEventsFired = 0;
             EventComponent component = null;
-            Action<UIEventArgs> eventHandler = null;
+            Action<EventArgs> eventHandler = null;
 
             eventHandler = _ =>
             {
@@ -2737,14 +2737,14 @@ namespace Microsoft.AspNetCore.Components.Test
             // Act/Assert 1: Event can be fired for the first time
             var render1TCS = new TaskCompletionSource<object>();
             renderer.NextUpdateDisplayReturnTask = render1TCS.Task;
-            await renderer.DispatchEventAsync(eventHandlerId, new UIEventArgs());
+            await renderer.DispatchEventAsync(eventHandlerId, new EventArgs());
             Assert.Equal(1, numEventsFired);
 
             // Act/Assert 2: *Same* event handler ID can be reused prior to completion of
             // preceding UI update
             var render2TCS = new TaskCompletionSource<object>();
             renderer.NextUpdateDisplayReturnTask = render2TCS.Task;
-            await renderer.DispatchEventAsync(eventHandlerId, new UIEventArgs());
+            await renderer.DispatchEventAsync(eventHandlerId, new EventArgs());
             Assert.Equal(2, numEventsFired);
 
             // Act/Assert 3: After we complete the first UI update in which a given
@@ -2760,7 +2760,7 @@ namespace Microsoft.AspNetCore.Components.Test
             await awaitableTask;
             var ex = await Assert.ThrowsAsync<ArgumentException>(() =>
             {
-                return renderer.DispatchEventAsync(eventHandlerId, new UIEventArgs());
+                return renderer.DispatchEventAsync(eventHandlerId, new EventArgs());
             });
             Assert.Equal($"There is no event handler with ID {eventHandlerId}", ex.Message);
             Assert.Equal(2, numEventsFired);
@@ -3318,7 +3318,7 @@ namespace Microsoft.AspNetCore.Components.Test
                 FieldValue = "new property value",
                 ComponentId = componentId
             };
-            var dispatchEventTask = renderer.DispatchEventAsync(eventHandlerId, eventFieldInfo, new UIChangeEventArgs
+            var dispatchEventTask = renderer.DispatchEventAsync(eventHandlerId, eventFieldInfo, new ChangeEventArgs
             {
                 Value = "new property value"
             });
@@ -3336,7 +3336,7 @@ namespace Microsoft.AspNetCore.Components.Test
                 // show that the diff does *not* update the BoundString value attribute.
                 Assert.Equal(RenderTreeEditType.SetAttribute, edit.Type);
                 var attributeFrame = batch2.ReferenceFrames[edit.ReferenceFrameIndex];
-                AssertFrame.Attribute(attributeFrame, "ontestevent", typeof(Action<UIChangeEventArgs>));
+                AssertFrame.Attribute(attributeFrame, "ontestevent", typeof(Action<ChangeEventArgs>));
                 Assert.NotEqual(default, attributeFrame.AttributeEventHandlerId);
                 Assert.NotEqual(eventHandlerId, attributeFrame.AttributeEventHandlerId);
             });
@@ -3370,7 +3370,7 @@ namespace Microsoft.AspNetCore.Components.Test
                     ComponentId = componentId,
                     FieldValue = newPropertyValue,
                 };
-                var dispatchEventTask = renderer.DispatchEventAsync(eventHandlerId, fieldInfo, new UIChangeEventArgs
+                var dispatchEventTask = renderer.DispatchEventAsync(eventHandlerId, fieldInfo, new ChangeEventArgs
                 {
                     Value = newPropertyValue
                 });
@@ -3388,7 +3388,7 @@ namespace Microsoft.AspNetCore.Components.Test
                     // show that the diff does *not* update the BoundString value attribute.
                     Assert.Equal(RenderTreeEditType.SetAttribute, edit.Type);
                     var attributeFrame = latestBatch.ReferenceFrames[edit.ReferenceFrameIndex];
-                    AssertFrame.Attribute(attributeFrame, "ontestevent", typeof(Action<UIChangeEventArgs>));
+                    AssertFrame.Attribute(attributeFrame, "ontestevent", typeof(Action<ChangeEventArgs>));
                     Assert.NotEqual(default, attributeFrame.AttributeEventHandlerId);
                     Assert.NotEqual(eventHandlerId, attributeFrame.AttributeEventHandlerId);
                 });
@@ -3507,10 +3507,10 @@ namespace Microsoft.AspNetCore.Components.Test
         private class EventComponent : AutoRenderComponent, IComponent, IHandleEvent
         {
             [Parameter]
-            public Action<UIEventArgs> OnTest { get; set; }
+            public Action<EventArgs> OnTest { get; set; }
 
             [Parameter]
-            public Func<UIEventArgs, Task> OnTestAsync { get; set; }
+            public Func<EventArgs, Task> OnTestAsync { get; set; }
 
             [Parameter]
             public Action<DerivedEventArgs> OnClick { get; set; }
@@ -3664,7 +3664,7 @@ namespace Microsoft.AspNetCore.Components.Test
                 => _renderHandle.Render(builder =>
                 {
                     builder.OpenElement(0, "my button");
-                    builder.AddAttribute(1, "my click handler", new Action<UIEventArgs>(eventArgs => OnClick(eventArgs)));
+                    builder.AddAttribute(1, "my click handler", new Action<EventArgs>(eventArgs => OnClick(eventArgs)));
                     builder.CloseElement();
                 });
         }
@@ -4095,7 +4095,7 @@ namespace Microsoft.AspNetCore.Components.Test
 
                 builder.OpenElement(0, "element with event");
                 builder.AddAttribute(1, nameof(BoundString), BoundString);
-                builder.AddAttribute(2, "ontestevent", new Action<UIChangeEventArgs>((UIChangeEventArgs eventArgs) =>
+                builder.AddAttribute(2, "ontestevent", new Action<ChangeEventArgs>((ChangeEventArgs eventArgs) =>
                 {
                     BoundString = (string)eventArgs.Value;
                     TriggerRender();
@@ -4106,7 +4106,7 @@ namespace Microsoft.AspNetCore.Components.Test
             }
         }
 
-        private class DerivedEventArgs : UIEventArgs
+        private class DerivedEventArgs : EventArgs
         {
         }
     }

src/Components/Components/test/Rendering/HtmlRendererTestBase.cs

@@ -343,7 +343,7 @@ namespace Microsoft.AspNetCore.Components.Rendering
             {
                 rtb.OpenElement(0, "p");
                 rtb.OpenElement(1, "input");
-                rtb.AddAttribute(2, "change", pc.GetValueOrDefault<Action<UIChangeEventArgs>>("update"));
+                rtb.AddAttribute(2, "change", pc.GetValueOrDefault<Action<ChangeEventArgs>>("update"));
                 rtb.AddAttribute(3, "value", pc.GetValueOrDefault<int>("value"));
                 rtb.CloseElement();
                 rtb.CloseElement();
@@ -354,7 +354,7 @@ namespace Microsoft.AspNetCore.Components.Rendering
                 .BuildServiceProvider();
 
             var htmlRenderer = GetHtmlRenderer(serviceProvider);
-            Action<UIChangeEventArgs> change = (UIChangeEventArgs changeArgs) => throw new InvalidOperationException();
+            Action<ChangeEventArgs> change = (ChangeEventArgs changeArgs) => throw new InvalidOperationException();
 
             // Act
             var result = GetResult(htmlRenderer.Dispatcher.InvokeAsync(() => htmlRenderer.RenderComponentAsync<ComponentWithParameters>(

src/Components/Shared/test/AssertFrame.cs

@@ -55,7 +55,7 @@ namespace Microsoft.AspNetCore.Components.Test.Helpers
             Assert.Equal(attributeValue, frame.AttributeValue);
         }
 
-        public static void Attribute(RenderTreeFrame frame, string attributeName, Action<UIEventArgs> attributeEventHandlerValue, int? sequence = null)
+        public static void Attribute(RenderTreeFrame frame, string attributeName, Action<EventArgs> attributeEventHandlerValue, int? sequence = null)
         {
             AssertFrame.Attribute(frame, attributeName, sequence);
             Assert.Equal(attributeEventHandlerValue, frame.AttributeValue);

src/Components/Shared/test/TestRenderer.cs

@@ -60,10 +60,10 @@ namespace Microsoft.AspNetCore.Components.Test.Helpers
         public new Task RenderRootComponentAsync(int componentId, ParameterView parameters)
             => Dispatcher.InvokeAsync(() => base.RenderRootComponentAsync(componentId, parameters));
 
-        public Task DispatchEventAsync(ulong eventHandlerId, UIEventArgs args)
+        public Task DispatchEventAsync(ulong eventHandlerId, EventArgs args)
             => Dispatcher.InvokeAsync(() => base.DispatchEventAsync(eventHandlerId, null, args));
 
-        public new Task DispatchEventAsync(ulong eventHandlerId, EventFieldInfo eventFieldInfo, UIEventArgs args)
+        public new Task DispatchEventAsync(ulong eventHandlerId, EventFieldInfo eventFieldInfo, EventArgs args)
             => Dispatcher.InvokeAsync(() => base.DispatchEventAsync(eventHandlerId, eventFieldInfo, args));
 
         private static Task UnwrapTask(Task task)

src/Components/Web/ref/Microsoft.AspNetCore.Components.Web.netstandard2.0.cs

@@ -53,23 +53,23 @@ namespace Microsoft.AspNetCore.Components
         public System.Type EventArgsType { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
     }
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onabort", typeof(Microsoft.AspNetCore.Components.UIProgressEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onactivate", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onactivate", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforeactivate", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforeactivate", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforecopy", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforecopy", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforecut", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforecut", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforedeactivate", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforedeactivate", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforepaste", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onbeforepaste", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onblur", typeof(Microsoft.AspNetCore.Components.UIFocusEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oncanplay", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oncanplay", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oncanplaythrough", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oncanplaythrough", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onchange", typeof(Microsoft.AspNetCore.Components.UIChangeEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onchange", typeof(Microsoft.AspNetCore.Components.ChangeEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onclick", typeof(Microsoft.AspNetCore.Components.UIMouseEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("oncontextmenu", typeof(Microsoft.AspNetCore.Components.UIMouseEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("oncopy", typeof(Microsoft.AspNetCore.Components.UIClipboardEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oncuechange", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oncuechange", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("oncut", typeof(Microsoft.AspNetCore.Components.UIClipboardEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondblclick", typeof(Microsoft.AspNetCore.Components.UIMouseEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondeactivate", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondeactivate", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondrag", typeof(Microsoft.AspNetCore.Components.UIDragEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondragend", typeof(Microsoft.AspNetCore.Components.UIDragEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondragenter", typeof(Microsoft.AspNetCore.Components.UIDragEventArgs))]
@@ -77,24 +77,24 @@ namespace Microsoft.AspNetCore.Components
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondragover", typeof(Microsoft.AspNetCore.Components.UIDragEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondragstart", typeof(Microsoft.AspNetCore.Components.UIDragEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondrop", typeof(Microsoft.AspNetCore.Components.UIDragEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondurationchange", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("ondurationchange", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onemptied", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onemptied", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onended", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onended", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onerror", typeof(Microsoft.AspNetCore.Components.UIErrorEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onfocus", typeof(Microsoft.AspNetCore.Components.UIFocusEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onfocusin", typeof(Microsoft.AspNetCore.Components.UIFocusEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onfocusout", typeof(Microsoft.AspNetCore.Components.UIFocusEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onfullscreenchange", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onfullscreenchange", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onfullscreenerror", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onfullscreenerror", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ongotpointercapture", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oninput", typeof(Microsoft.AspNetCore.Components.UIChangeEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oninput", typeof(Microsoft.AspNetCore.Components.ChangeEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oninvalid", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("oninvalid", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onkeydown", typeof(Microsoft.AspNetCore.Components.UIKeyboardEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onkeypress", typeof(Microsoft.AspNetCore.Components.UIKeyboardEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onkeyup", typeof(Microsoft.AspNetCore.Components.UIKeyboardEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onload", typeof(Microsoft.AspNetCore.Components.UIProgressEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onloadeddata", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onloadeddata", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onloadedmetadata", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onloadedmetadata", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onloadend", typeof(Microsoft.AspNetCore.Components.UIProgressEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onloadstart", typeof(Microsoft.AspNetCore.Components.UIProgressEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onlostpointercapture", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
@@ -105,50 +105,51 @@ namespace Microsoft.AspNetCore.Components
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onmouseup", typeof(Microsoft.AspNetCore.Components.UIMouseEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onmousewheel", typeof(Microsoft.AspNetCore.Components.UIWheelEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpaste", typeof(Microsoft.AspNetCore.Components.UIClipboardEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpause", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpause", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onplay", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onplay", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onplaying", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onplaying", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointercancel", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerdown", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerenter", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerleave", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerlockchange", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerlockchange", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerlockerror", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerlockerror", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointermove", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerout", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerover", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onpointerup", typeof(Microsoft.AspNetCore.Components.UIPointerEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onprogress", typeof(Microsoft.AspNetCore.Components.UIProgressEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onratechange", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onratechange", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onreadystatechange", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onreadystatechange", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onreset", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onreset", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onscroll", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onscroll", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onseeked", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onseeked", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onseeking", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onseeking", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onselect", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onselect", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onselectionchange", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onselectionchange", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onselectstart", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onselectstart", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onstalled", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onstalled", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onstop", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onstop", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onsubmit", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onsubmit", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onsuspend", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onsuspend", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ontimeout", typeof(Microsoft.AspNetCore.Components.UIProgressEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("ontimeupdate", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("ontimeupdate", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ontouchcancel", typeof(Microsoft.AspNetCore.Components.UITouchEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ontouchend", typeof(Microsoft.AspNetCore.Components.UITouchEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ontouchenter", typeof(Microsoft.AspNetCore.Components.UITouchEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ontouchleave", typeof(Microsoft.AspNetCore.Components.UITouchEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ontouchmove", typeof(Microsoft.AspNetCore.Components.UITouchEventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("ontouchstart", typeof(Microsoft.AspNetCore.Components.UITouchEventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onvolumechange", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onvolumechange", typeof(System.EventArgs))]
-    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onwaiting", typeof(Microsoft.AspNetCore.Components.UIEventArgs))]
+    [Microsoft.AspNetCore.Components.EventHandlerAttribute("onwaiting", typeof(System.EventArgs))]
     [Microsoft.AspNetCore.Components.EventHandlerAttribute("onwheel", typeof(Microsoft.AspNetCore.Components.UIWheelEventArgs))]
     public static partial class EventHandlers
     {
     }
-    public partial class UIClipboardEventArgs : Microsoft.AspNetCore.Components.UIEventArgs
+    public partial class UIClipboardEventArgs : System.EventArgs
     {
         public UIClipboardEventArgs() { }
+        public string Type { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
     }
     public partial class UIDataTransferItem
     {
@@ -161,19 +162,21 @@ namespace Microsoft.AspNetCore.Components
         public UIDragEventArgs() { }
         public Microsoft.AspNetCore.Components.DataTransfer DataTransfer { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
     }
-    public partial class UIErrorEventArgs : Microsoft.AspNetCore.Components.UIEventArgs
+    public partial class UIErrorEventArgs : System.EventArgs
     {
         public UIErrorEventArgs() { }
         public int Colno { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public string Filename { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public int Lineno { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public string Message { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
+        public string Type { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
     }
-    public partial class UIFocusEventArgs : Microsoft.AspNetCore.Components.UIEventArgs
+    public partial class UIFocusEventArgs : System.EventArgs
     {
         public UIFocusEventArgs() { }
+        public string Type { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
     }
-    public partial class UIKeyboardEventArgs : Microsoft.AspNetCore.Components.UIEventArgs
+    public partial class UIKeyboardEventArgs : System.EventArgs
     {
         public UIKeyboardEventArgs() { }
         public bool AltKey { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
@@ -184,8 +187,9 @@ namespace Microsoft.AspNetCore.Components
         public bool MetaKey { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public bool Repeat { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public bool ShiftKey { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
+        public string Type { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
     }
-    public partial class UIMouseEventArgs : Microsoft.AspNetCore.Components.UIEventArgs
+    public partial class UIMouseEventArgs : System.EventArgs
     {
         public UIMouseEventArgs() { }
         public bool AltKey { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
@@ -199,6 +203,7 @@ namespace Microsoft.AspNetCore.Components
         public double ScreenX { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public double ScreenY { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public bool ShiftKey { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
+        public string Type { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
     }
     public partial class UIPointerEventArgs : Microsoft.AspNetCore.Components.UIMouseEventArgs
     {
@@ -212,14 +217,15 @@ namespace Microsoft.AspNetCore.Components
         public float TiltY { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public float Width { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
     }
-    public partial class UIProgressEventArgs : Microsoft.AspNetCore.Components.UIEventArgs
+    public partial class UIProgressEventArgs : System.EventArgs
     {
         public UIProgressEventArgs() { }
         public bool LengthComputable { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public long Loaded { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public long Total { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
+        public string Type { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
     }
-    public partial class UITouchEventArgs : Microsoft.AspNetCore.Components.UIEventArgs
+    public partial class UITouchEventArgs : System.EventArgs
     {
         public UITouchEventArgs() { }
         public bool AltKey { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
@@ -230,6 +236,7 @@ namespace Microsoft.AspNetCore.Components
         public bool ShiftKey { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public Microsoft.AspNetCore.Components.UITouchPoint[] TargetTouches { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public Microsoft.AspNetCore.Components.UITouchPoint[] Touches { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
+        public string Type { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
     }
     public partial class UITouchPoint
     {

src/Components/Web/src/EventHandlers.cs

@@ -43,19 +43,19 @@ namespace Microsoft.AspNetCore.Components
     [EventHandler("onkeypress", typeof(UIKeyboardEventArgs))]
 
     // Input events
-    [EventHandler("onchange", typeof(UIChangeEventArgs))]
+    [EventHandler("onchange", typeof(ChangeEventArgs))]
-    [EventHandler("oninput", typeof(UIChangeEventArgs))]
+    [EventHandler("oninput", typeof(ChangeEventArgs))]
-    [EventHandler("oninvalid", typeof(UIEventArgs))]
+    [EventHandler("oninvalid", typeof(EventArgs))]
-    [EventHandler("onreset", typeof(UIEventArgs))]
+    [EventHandler("onreset", typeof(EventArgs))]
-    [EventHandler("onselect", typeof(UIEventArgs))]
+    [EventHandler("onselect", typeof(EventArgs))]
-    [EventHandler("onselectstart", typeof(UIEventArgs))]
+    [EventHandler("onselectstart", typeof(EventArgs))]
-    [EventHandler("onselectionchange", typeof(UIEventArgs))]
+    [EventHandler("onselectionchange", typeof(EventArgs))]
-    [EventHandler("onsubmit", typeof(UIEventArgs))]
+    [EventHandler("onsubmit", typeof(EventArgs))]
 
     // Clipboard events
-    [EventHandler("onbeforecopy", typeof(UIEventArgs))]
+    [EventHandler("onbeforecopy", typeof(EventArgs))]
-    [EventHandler("onbeforecut", typeof(UIEventArgs))]
+    [EventHandler("onbeforecut", typeof(EventArgs))]
-    [EventHandler("onbeforepaste", typeof(UIEventArgs))]
+    [EventHandler("onbeforepaste", typeof(EventArgs))]
     [EventHandler("oncopy", typeof(UIClipboardEventArgs))]
     [EventHandler("oncut", typeof(UIClipboardEventArgs))]
     [EventHandler("onpaste", typeof(UIClipboardEventArgs))]
@@ -81,23 +81,23 @@ namespace Microsoft.AspNetCore.Components
     [EventHandler("onpointerup", typeof(UIPointerEventArgs))]
 
     // Media events
-    [EventHandler("oncanplay", typeof(UIEventArgs))]
+    [EventHandler("oncanplay", typeof(EventArgs))]
-    [EventHandler("oncanplaythrough", typeof(UIEventArgs))]
+    [EventHandler("oncanplaythrough", typeof(EventArgs))]
-    [EventHandler("oncuechange", typeof(UIEventArgs))]
+    [EventHandler("oncuechange", typeof(EventArgs))]
-    [EventHandler("ondurationchange", typeof(UIEventArgs))]
+    [EventHandler("ondurationchange", typeof(EventArgs))]
-    [EventHandler("onemptied", typeof(UIEventArgs))]
+    [EventHandler("onemptied", typeof(EventArgs))]
-    [EventHandler("onpause", typeof(UIEventArgs))]
+    [EventHandler("onpause", typeof(EventArgs))]
-    [EventHandler("onplay", typeof(UIEventArgs))]
+    [EventHandler("onplay", typeof(EventArgs))]
-    [EventHandler("onplaying", typeof(UIEventArgs))]
+    [EventHandler("onplaying", typeof(EventArgs))]
-    [EventHandler("onratechange", typeof(UIEventArgs))]
+    [EventHandler("onratechange", typeof(EventArgs))]
-    [EventHandler("onseeked", typeof(UIEventArgs))]
+    [EventHandler("onseeked", typeof(EventArgs))]
-    [EventHandler("onseeking", typeof(UIEventArgs))]
+    [EventHandler("onseeking", typeof(EventArgs))]
-    [EventHandler("onstalled", typeof(UIEventArgs))]
+    [EventHandler("onstalled", typeof(EventArgs))]
-    [EventHandler("onstop", typeof(UIEventArgs))]
+    [EventHandler("onstop", typeof(EventArgs))]
-    [EventHandler("onsuspend", typeof(UIEventArgs))]
+    [EventHandler("onsuspend", typeof(EventArgs))]
-    [EventHandler("ontimeupdate", typeof(UIEventArgs))]
+    [EventHandler("ontimeupdate", typeof(EventArgs))]
-    [EventHandler("onvolumechange", typeof(UIEventArgs))]
+    [EventHandler("onvolumechange", typeof(EventArgs))]
-    [EventHandler("onwaiting", typeof(UIEventArgs))]
+    [EventHandler("onwaiting", typeof(EventArgs))]
 
     // Progress events
     [EventHandler("onloadstart", typeof(UIProgressEventArgs))]
@@ -109,19 +109,19 @@ namespace Microsoft.AspNetCore.Components
     [EventHandler("onerror", typeof(UIErrorEventArgs))]
 
     // General events
-    [EventHandler("onactivate", typeof(UIEventArgs))]
+    [EventHandler("onactivate", typeof(EventArgs))]
-    [EventHandler("onbeforeactivate", typeof(UIEventArgs))]
+    [EventHandler("onbeforeactivate", typeof(EventArgs))]
-    [EventHandler("onbeforedeactivate", typeof(UIEventArgs))]
+    [EventHandler("onbeforedeactivate", typeof(EventArgs))]
-    [EventHandler("ondeactivate", typeof(UIEventArgs))]
+    [EventHandler("ondeactivate", typeof(EventArgs))]
-    [EventHandler("onended", typeof(UIEventArgs))]
+    [EventHandler("onended", typeof(EventArgs))]
-    [EventHandler("onfullscreenchange", typeof(UIEventArgs))]
+    [EventHandler("onfullscreenchange", typeof(EventArgs))]
-    [EventHandler("onfullscreenerror", typeof(UIEventArgs))]
+    [EventHandler("onfullscreenerror", typeof(EventArgs))]
-    [EventHandler("onloadeddata", typeof(UIEventArgs))]
+    [EventHandler("onloadeddata", typeof(EventArgs))]
-    [EventHandler("onloadedmetadata", typeof(UIEventArgs))]
+    [EventHandler("onloadedmetadata", typeof(EventArgs))]
-    [EventHandler("onpointerlockchange", typeof(UIEventArgs))]
+    [EventHandler("onpointerlockchange", typeof(EventArgs))]
-    [EventHandler("onpointerlockerror", typeof(UIEventArgs))]
+    [EventHandler("onpointerlockerror", typeof(EventArgs))]
-    [EventHandler("onreadystatechange", typeof(UIEventArgs))]
+    [EventHandler("onreadystatechange", typeof(EventArgs))]
-    [EventHandler("onscroll", typeof(UIEventArgs))]
+    [EventHandler("onscroll", typeof(EventArgs))]
     public static class EventHandlers
     {
     }

src/Components/Web/src/RendererRegistryEventDispatcher.cs

@@ -54,12 +54,12 @@ namespace Microsoft.AspNetCore.Components.Web
             }
         }
 
-        private static UIEventArgs ParseEventArgsJson(string eventArgsType, string eventArgsJson)
+        private static EventArgs ParseEventArgsJson(string eventArgsType, string eventArgsJson)
         {
             switch (eventArgsType)
             {
                 case "change":
-                    return DeserializeUIEventChangeArgs(eventArgsJson);
+                    return DeserializeChangeEventArgs(eventArgsJson);
                 case "clipboard":
                     return Deserialize<UIClipboardEventArgs>(eventArgsJson);
                 case "drag":
@@ -79,7 +79,7 @@ namespace Microsoft.AspNetCore.Components.Web
                 case "touch":
                     return Deserialize<UITouchEventArgs>(eventArgsJson);
                 case "unknown":
-                    return Deserialize<UIEventArgs>(eventArgsJson);
+                    return EventArgs.Empty;
                 case "wheel":
                     return Deserialize<UIWheelEventArgs>(eventArgsJson);
                 default:
@@ -92,9 +92,9 @@ namespace Microsoft.AspNetCore.Components.Web
             return JsonSerializer.Deserialize<T>(eventArgsJson, JsonSerializerOptionsProvider.Options);
         }
 
-        private static UIChangeEventArgs DeserializeUIEventChangeArgs(string eventArgsJson)
+        private static ChangeEventArgs DeserializeChangeEventArgs(string eventArgsJson)
         {
-            var changeArgs = Deserialize<UIChangeEventArgs>(eventArgsJson);
+            var changeArgs = Deserialize<ChangeEventArgs>(eventArgsJson);
             var jsonElement = (JsonElement)changeArgs.Value;
             switch (jsonElement.ValueKind)
             {
@@ -109,7 +109,7 @@ namespace Microsoft.AspNetCore.Components.Web
                     changeArgs.Value = jsonElement.GetBoolean();
                     break;
                 default:
-                    throw new ArgumentException($"Unsupported {nameof(UIChangeEventArgs)} value {jsonElement}.");
+                    throw new ArgumentException($"Unsupported {nameof(ChangeEventArgs)} value {jsonElement}.");
             }
             return changeArgs;
         }

src/Components/Web/src/UIClipboardEventArgs.cs

@@ -1,12 +1,18 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
     /// Supplies information about an clipboard event that is being raised.
     /// </summary>
-    public class UIClipboardEventArgs : UIEventArgs
+    public class UIClipboardEventArgs : EventArgs
     {
+        /// <summary>
+        /// Gets or sets the type of the event.
+        /// </summary>
+        public string Type { get; set; }
     }
 }

src/Components/Web/src/UIErrorEventArgs.cs

@@ -1,12 +1,14 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
     /// Supplies information about an error event that is being raised.
     /// </summary>
-    public class UIErrorEventArgs : UIEventArgs
+    public class UIErrorEventArgs : EventArgs
     {
         /// <summary>
         /// Gets a a human-readable error message describing the problem.
@@ -27,5 +29,10 @@ namespace Microsoft.AspNetCore.Components
         /// Gets the column number of the script file on which the error occurred.
         /// </summary>
         public int Colno { get; set; }
+
+        /// <summary>
+        /// Gets or sets the type of the event.
+        /// </summary>
+        public string Type { get; set; }
     }
 }

src/Components/Web/src/UIFocusEventArgs.cs

@@ -1,14 +1,21 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
     /// Supplies information about a focus event that is being raised.
     /// </summary>
-    public class UIFocusEventArgs : UIEventArgs
+    public class UIFocusEventArgs : EventArgs
     {
         // Not including support for 'relatedTarget' since we don't have a good way to represent it.
         // see: https://developer.mozilla.org/en-US/docs/Web/API/FocusEvent
+
+        /// <summary>
+        /// Gets or sets the type of the event.
+        /// </summary>
+        public string Type { get; set; }
     }
 }

src/Components/Web/src/UIKeyboardEventArgs.cs

@@ -1,12 +1,14 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
     /// Supplies information about a keyboard event that is being raised.
     /// </summary>
-    public class UIKeyboardEventArgs : UIEventArgs
+    public class UIKeyboardEventArgs : EventArgs
     {
         /// <summary>
         /// The key value of the key represented by the event. 
@@ -51,5 +53,10 @@ namespace Microsoft.AspNetCore.Components
         /// true if the meta key was down when the event was fired. false otherwise.
         /// </summary>
         public bool MetaKey { get; set; }
+
+        /// <summary>
+        /// Gets or sets the type of the event.
+        /// </summary>
+        public string Type { get; set; }
     }
 }

src/Components/Web/src/UIMouseEventArgs.cs

@@ -1,12 +1,14 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
     /// Supplies information about a mouse event that is being raised.
     /// </summary>
-    public class UIMouseEventArgs : UIEventArgs
+    public class UIMouseEventArgs : EventArgs
     {
         /// <summary>
         /// A count of consecutive clicks that happened in a short amount of time, incremented by one.
@@ -73,5 +75,10 @@ namespace Microsoft.AspNetCore.Components
         /// <c>true</c> if the meta key was down when the event was fired. <c>false</c> otherwise.
         /// </summary>
         public bool MetaKey { get; set; }
+
+        /// <summary>
+        /// Gets or sets the type of the event.
+        /// </summary>
+        public string Type { get; set; }
     }
 }

src/Components/Web/src/UIProgressEventArgs.cs

@@ -1,12 +1,14 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
     /// Supplies information about a progress event that is being raised.
     /// </summary>
-    public class UIProgressEventArgs : UIEventArgs
+    public class UIProgressEventArgs : EventArgs
     {
         /// <summary>
         /// Whether or not the total size of the transfer is known.
@@ -24,5 +26,10 @@ namespace Microsoft.AspNetCore.Components
         /// If the total size is unknown, this value is zero. 
         /// </summary>
         public long Total { get; set; }
+
+        /// <summary>
+        /// Gets or sets the type of the event.
+        /// </summary>
+        public string Type { get; set; }
     }
 }

src/Components/Web/src/UITouchEventArgs.cs

@@ -1,12 +1,14 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
     /// Supplies information about a touch event that is being raised.
     /// </summary>
-    public class UITouchEventArgs : UIEventArgs
+    public class UITouchEventArgs : EventArgs
     {
         /// <summary>
         /// A count of consecutive clicks that happened in a short amount of time, incremented by one.
@@ -50,5 +52,10 @@ namespace Microsoft.AspNetCore.Components
         /// true if the meta key was down when the event was fired. false otherwise.
         /// </summary>
         public bool MetaKey { get; set; }
+
+        /// <summary>
+        /// Gets or sets the type of the event.
+        /// </summary>
+        public string Type { get; set; }
     }
 }

src/Components/Web/src/WebEventCallbackFactoryUIEventArgsExtensions.cs

@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 namespace Microsoft.AspNetCore.Components
 {
     /// <summary>
-    /// Provides extension methods for <see cref="EventCallbackFactory"/> and <see cref="UIEventArgs"/> types.
+    /// Provides extension methods for <see cref="EventCallbackFactory"/> and <see cref="EventArgs"/> types.
     /// </summary>
     public static class WebEventCallbackFactoryUIEventArgsExtensions
     {

src/Components/test/E2ETest/ServerExecutionTests/InteropReliabilityTests.cs

@@ -385,7 +385,7 @@ namespace Microsoft.AspNetCore.Components.E2ETest.ServerExecutionTests
         }
 
         [Fact]
-        public async Task DispatchingEventsWithInvalidUIEventArgs()
+        public async Task DispatchingEventsWithInvalidEventArgs()
         {
             // Arrange
             var (interopCalls, dotNetCompletions, batches) = ConfigureClient();

src/Components/test/testassets/BasicTestApp/CulturePicker.razor

@@ -8,7 +8,7 @@
 </select>
 
 @code {
-    void OnSelected(UIChangeEventArgs e)
+    void OnSelected(ChangeEventArgs e)
     {
         // Included fragment to preserve choice of Blazor client or server.
         var redirect = new Uri(UriHelper.GetAbsoluteUri()).GetComponents(UriComponents.PathAndQuery | UriComponents.Fragment, UriFormat.UriEscaped);

src/Components/test/testassets/Ignitor/ElementNode.cs

@@ -70,9 +70,8 @@ namespace Ignitor
                 throw new InvalidOperationException("Element does not have a change event.");
             }
 
-            var sleectEventArgs = new UIChangeEventArgs()
+            var args = new ChangeEventArgs()
             {
-                Type = changeEventDescriptor.EventName,
                 Value = value
             };
 
@@ -88,7 +87,7 @@ namespace Ignitor
                 }
             };
 
-            return DispatchEventCore(connection, Serialize(browserDescriptor), Serialize(sleectEventArgs));
+            return DispatchEventCore(connection, Serialize(browserDescriptor), Serialize(args));
         }
 
         public Task ClickAsync(HubConnection connection)