Modified FormCollectionModelBinderProvider to throw when binding for FormCollection model type.

[Fixes #4895] No parameterless Constructor defined

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/FormCollectionModelBinderProvider.cs

@@ -2,7 +2,9 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Reflection;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.Core;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 {
@@ -19,7 +21,18 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 throw new ArgumentNullException(nameof(context));
             }
 
-            if (context.Metadata.ModelType == typeof(IFormCollection))
+            var modelType = context.Metadata.ModelType;
+
+            if (typeof(FormCollection).GetTypeInfo().IsAssignableFrom(modelType))
+            {
+                throw new InvalidOperationException(
+                    Resources.FormatFormCollectionModelBinder_CannotBindToFormCollection(
+                        typeof(FormCollectionModelBinder).FullName,
+                        modelType.FullName,
+                        typeof(IFormCollection).FullName));
+            }
+
+            if (modelType == typeof(IFormCollection))
             {
                 return new FormCollectionModelBinder();
             }

src/Microsoft.AspNetCore.Mvc.Core/Properties/Resources.Designer.cs

@@ -1322,6 +1322,22 @@ namespace Microsoft.AspNetCore.Mvc.Core
             return string.Format(CultureInfo.CurrentCulture, GetString("AuthorizeFilter_AuthorizationPolicyCannotBeCreated"), p0, p1);
         }
 
+        /// <summary>
+        /// The '{0}' cannot bind to a model of type '{1}'. Change the model type to '{2}' instead.
+        /// </summary>
+        internal static string FormCollectionModelBinder_CannotBindToFormCollection
+        {
+            get { return GetString("FormCollectionModelBinder_CannotBindToFormCollection"); }
+        }
+
+        /// <summary>
+        /// The '{0}' cannot bind to a model of type '{1}'. Change the model type to '{2}' instead.
+        /// </summary>
+        internal static string FormatFormCollectionModelBinder_CannotBindToFormCollection(object p0, object p1, object p2)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("FormCollectionModelBinder_CannotBindToFormCollection"), p0, p1, p2);
+        }
+
         private static string GetString(string name, params string[] formatterNames)
         {
             var value = _resourceManager.GetString(name);

src/Microsoft.AspNetCore.Mvc.Core/Resources.resx

@@ -373,4 +373,7 @@
   <data name="AuthorizeFilter_AuthorizationPolicyCannotBeCreated" xml:space="preserve">
     <value>An {0} cannot be created without a valid instance of {1}.</value>
   </data>
+  <data name="FormCollectionModelBinder_CannotBindToFormCollection" xml:space="preserve">
+    <value>The '{0}' cannot bind to a model of type '{1}'. Change the model type to '{2}' instead.</value>
+  </data>
 </root>

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/FormCollectionModelBinderProviderTest.cs

@@ -12,6 +12,22 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
     {
         [Theory]
         [InlineData(typeof(FormCollection))]
+        [InlineData(typeof(DerviedFormCollection))]
+        public void Create_ThrowsException_ForFormCollectionModelType(Type modelType)
+        {
+            // Arrange
+            var provider = new FormCollectionModelBinderProvider();
+            var context = new TestModelBinderProviderContext(modelType);
+
+            // Act & Assert
+            var exception = Assert.Throws<InvalidOperationException>(() => provider.GetBinder(context));
+
+            Assert.Equal(
+                $"The '{typeof(FormCollectionModelBinder).FullName}' cannot bind to a model of type '{modelType.FullName}'. Change the model type to '{typeof(IFormCollection).FullName}' instead.",
+                exception.Message);
+        }
+
+        [Theory]
         [InlineData(typeof(TestClass))]
         [InlineData(typeof(IList<int>))]
         [InlineData(typeof(int[]))]
@@ -45,5 +61,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
         private class TestClass
         {
         }
+
+        private class DerviedFormCollection : FormCollection
+        {
+            public DerviedFormCollection() : base(fields: null, files: null) { }
+        }
     }
 }