React to string[] -> StringValues changes.

src/Microsoft.AspNet.Mvc.Abstractions/ModelBinding/ModelStateDictionary.cs

@@ -385,26 +385,22 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// </param>
         public void SetModelValue([NotNull] string key, ValueProviderResult valueProviderResult)
         {
-            // Avoid creating a new array for rawvalue if there's only one value.
+            // Avoid creating a new array for rawValue if there's only one value.
             object rawValue;
             if (valueProviderResult == ValueProviderResult.None)
             {
                 rawValue = null;
             }
-            else if (valueProviderResult.Value != null)
-            {
-                rawValue = valueProviderResult.Value;
-            }
             else if (valueProviderResult.Length == 1)
             {
                 rawValue = valueProviderResult.Values[0];
             }
             else
             {
-                rawValue = valueProviderResult.Values;
+                rawValue = valueProviderResult.Values.ToArray();
             }
 
-            SetModelValue(key, rawValue, (string)valueProviderResult);
+            SetModelValue(key, rawValue, valueProviderResult.ToString());
         }
 
         /// <summary>

src/Microsoft.AspNet.Mvc.Abstractions/ModelBinding/ValueProviderResult.cs

@@ -4,9 +4,8 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Globalization;
-using Microsoft.Framework.Internal;
+using Microsoft.Framework.Primitives;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
@@ -38,9 +37,9 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// <summary>
         /// Creates a new <see cref="ValueProviderResult"/> using <see cref="CultureInfo.InvariantCulture"/>.
         /// </summary>
-        /// <param name="value">The submitted value.</param>
+        /// <param name="values">The submitted values.</param>
-        public ValueProviderResult(string value)
+        public ValueProviderResult(StringValues values)
-            : this(value, _invariantCulture)
+            : this(values, _invariantCulture)
         {
         }
 
@@ -49,88 +48,36 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// </summary>
         /// <param name="value">The submitted value.</param>
         /// <param name="culture">The <see cref="CultureInfo"/> associated with this value.</param>
-        public ValueProviderResult(string value, CultureInfo culture)
+        public ValueProviderResult(StringValues values, CultureInfo culture)
         {
-            if (value == null)
+            Values = values;
-            {
-                Value = null;
-                Values = None.Values;
-            }
-            else
-            {
-                Value = value;
-                Values = null;
-            }
-
             Culture = culture ?? _invariantCulture;
         }
 
-        /// <summary>
-        /// Creates a new <see cref="ValueProviderResult"/> using <see cref="CultureInfo.InvariantCulture"/>.
-        /// </summary>
-        /// <param name="values">The submitted values.</param>
-        public ValueProviderResult(string[] values)
-            : this(values, _invariantCulture)
-        {
-        }
-
-        /// <summary>
-        /// Creates a new <see cref="ValueProviderResult"/>.
-        /// </summary>
-        /// <param name="values">The submitted values.</param>
-        /// <param name="culture">The <see cref="CultureInfo"/> associated with these values.</param>
-        public ValueProviderResult(string[] values, CultureInfo culture)
-        {
-            if (values == null)
-            {
-                Value = null;
-                Values = None.Values;
-            }
-            else
-            {
-                Value = null;
-                Values = values;
-            }
-
-            Culture = culture;
-        }
-
         /// <summary>
         /// Gets or sets the <see cref="CultureInfo"/> associated with the values.
         /// </summary>
         public CultureInfo Culture { get; private set; }
 
         /// <summary>
-        /// Gets or sets a single value. Will be <c>null</c> if multiple values are present.
+        /// Gets or sets the values.
         /// </summary>
-        public string Value { get; private set; }
+        public StringValues Values { get; private set; }
-
-        /// <summary>
-        /// Gets or sets an array of values. Will be <c>null</c> if only a single value was provided.
-        /// </summary>
-        public string[] Values { get; private set; }
 
         /// <summary>
         /// Gets the first value based on the order values were provided in the request. Use <see cref="FirstValue"/>
-        /// to get a single value for processing regarless of whether a single or multiple values were provided
+        /// to get a single value for processing regardless of whether a single or multiple values were provided
         /// in the request.
         /// </summary>
         public string FirstValue
         {
             get
             {
-                if (Value != null)
+                if (Values.Count == 0)
-                {
-                    return Value;
-                }
-                else if (Values != null && Values.Length > 0)
-                {
-                    return Values[0];
-                }
-                else
                 {
                     return null;
                 }
+                return Values[0];
             }
         }
 
@@ -141,18 +88,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         {
             get
             {
-                if (Values != null)
+                return Values.Count;
-                {
-                    return Values.Length;
-                }
-                else if (Value != null)
-                {
-                    return 1;
-                }
-                else
-                {
-                    return 0;
-                }
             }
         }
 
@@ -172,9 +108,9 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             }
             else
             {
-                var x = (string[])this;
+                var x = Values;
-                var y = (string[])other;
+                var y = other.Values;
-                for (var i = 0; i < x.Length; i++)
+                for (var i = 0; i < x.Count; i++)
                 {
                     if (!string.Equals(x[i], y[i], StringComparison.Ordinal))
                     {
@@ -188,28 +124,22 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// <inheritdoc />
         public override int GetHashCode()
         {
-            return ((string)this)?.GetHashCode() ?? 0;
+            return ToString().GetHashCode();
         }
 
         /// <inheritdoc />
         public override string ToString()
         {
-            return (string)this;
+            return Values.ToString();
         }
 
         /// <summary>
-        /// Gets an <see cref="Enumerator"/> for this <see cref="ValueProviderResult"/>.
+        /// Gets an <see cref="IEnumerator<string>"/> for this <see cref="ValueProviderResult"/>.
         /// </summary>
-        /// <returns>An <see cref="Enumerator"/>.</returns>
+        /// <returns>An <see cref="IEnumerator<string>"/>.</returns>
-        public Enumerator GetEnumerator()
+        public IEnumerator<string> GetEnumerator()
         {
-            return new Enumerator(this);
+            return ((IEnumerable<string>)Values).GetEnumerator();
-        }
-
-        /// <inheritdoc />
-        IEnumerator<string> IEnumerable<string>.GetEnumerator()
-        {
-            return GetEnumerator();
         }
 
         /// <inheritdoc />
@@ -225,22 +155,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// <param name="result">The <see cref="ValueProviderResult"/>.</param>
         public static explicit operator string(ValueProviderResult result)
         {
-            if (result.Values == null)
+            return result.Values;
-            {
-                return result.Value;
-            }
-            else if (result.Values.Length == 0)
-            {
-                return null;
-            }
-            else if (result.Values.Length == 1)
-            {
-                return result.Values[0];
-            }
-            else
-            {
-                return string.Join(",", result.Values);
-            }
         }
 
         /// <summary>
@@ -250,18 +165,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// <param name="result">The <see cref="ValueProviderResult"/>.</param>
         public static explicit operator string[](ValueProviderResult result)
         {
-            if (result.Values != null)
+            return result.Values;
-            {
-                return result.Values;
-            }
-            else if (result.Value != null)
-            {
-                return new string[] { result.Value };
-            }
-            else
-            {
-                return None.Values;
-            }
         }
 
         /// <summary>
@@ -285,71 +189,5 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         {
             return !x.Equals(y);
         }
-
-        /// <summary>
-        /// An enumerator for <see cref="ValueProviderResult"/>.
-        /// </summary>
-        public struct Enumerator : IEnumerator<string>
-        {
-            private readonly ValueProviderResult _result;
-            private readonly int _length;
-            private int _index;
-
-            /// <summary>
-            /// Creates a new <see cref="Enumerator"/>.
-            /// </summary>
-            /// <param name="result">The <see cref="ValueProviderResult"/>.</param>
-            public Enumerator(ValueProviderResult result)
-            {
-                _result = result;
-                _index = -1;
-                _length = result.Length;
-                Current = null;
-            }
-
-            /// <inheritdoc />
-            public string Current { get; private set; }
-
-            /// <inheritdoc />
-            object IEnumerator.Current => Current;
-
-            /// <inheritdoc />
-            public void Dispose()
-            {
-            }
-
-            /// <inheritdoc />
-            public bool MoveNext()
-            {
-                ++_index;
-                if (_index < _length)
-                {
-                    if (_result.Values != null)
-                    {
-                        Debug.Assert(_index < _result.Values.Length);
-                        Current = _result.Values[_index];
-                        return true;
-                    }
-                    else if (_result.Value != null && _index == 0)
-                    {
-                        Current = _result.Value;
-                        return true;
-                    }
-                    else
-                    {
-                        return false;
-                    }
-                }
-
-                Current = null;
-                return false;
-            }
-
-            /// <inheritdoc />
-            public void Reset()
-            {
-                _index = -1;
-            }
-        }
     }
 }

src/Microsoft.AspNet.Mvc.Core/CreatedAtActionResult.cs

@@ -7,6 +7,7 @@ using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc.Core;
 using Microsoft.Framework.DependencyInjection;
 using Microsoft.Framework.Internal;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNet.Mvc
 {
@@ -73,7 +74,7 @@ namespace Microsoft.AspNet.Mvc
                 throw new InvalidOperationException(Resources.NoRoutesMatched);
             }
 
-            context.HttpContext.Response.Headers.Set("Location", url);
+            context.HttpContext.Response.Headers[HeaderNames.Location] = url;
         }
     }
 }

src/Microsoft.AspNet.Mvc.Core/CreatedAtRouteResult.cs

@@ -7,6 +7,7 @@ using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc.Core;
 using Microsoft.Framework.DependencyInjection;
 using Microsoft.Framework.Internal;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNet.Mvc
 {
@@ -70,7 +71,7 @@ namespace Microsoft.AspNet.Mvc
                 throw new InvalidOperationException(Resources.NoRoutesMatched);
             }
 
-            context.HttpContext.Response.Headers.Set("Location", url);
+            context.HttpContext.Response.Headers[HeaderNames.Location] = url;
         }
     }
 }

src/Microsoft.AspNet.Mvc.Core/CreatedResult.cs

@@ -4,6 +4,7 @@
 using System;
 using Microsoft.AspNet.Http;
 using Microsoft.Framework.Internal;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNet.Mvc
 {
@@ -50,7 +51,7 @@ namespace Microsoft.AspNet.Mvc
         /// <inheritdoc />
         protected override void OnFormatting([NotNull] ActionContext context)
         {
-            context.HttpContext.Response.Headers.Set("Location", Location);
+            context.HttpContext.Response.Headers[HeaderNames.Location] = Location;
         }
     }
 }

src/Microsoft.AspNet.Mvc.Core/FileResult.cs

@@ -68,7 +68,7 @@ namespace Microsoft.AspNet.Mvc
                 // basis for the actual filename, where possible.
                 var cd = new ContentDispositionHeaderValue("attachment");
                 cd.SetHttpFileName(FileDownloadName);
-                context.HttpContext.Response.Headers.Set(HeaderNames.ContentDisposition, cd.ToString());
+                context.HttpContext.Response.Headers[HeaderNames.ContentDisposition] = cd.ToString();
             }
 
             // We aren't flowing the cancellation token appropriately, see

src/Microsoft.AspNet.Mvc.Core/HttpMethodConstraint.cs

@@ -6,6 +6,7 @@ using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
 using Microsoft.Framework.Internal;
+using Microsoft.Framework.Primitives;
 
 namespace Microsoft.AspNet.Mvc
 {
@@ -62,12 +63,12 @@ namespace Microsoft.AspNet.Mvc
             if (request.Headers.ContainsKey(OriginHeader))
             {
                 // Update the http method if it is preflight request.
-                var accessControlRequestMethod = request.Headers.Get(AccessControlRequestMethod);
+                var accessControlRequestMethod = request.Headers[AccessControlRequestMethod];
                 if (string.Equals(
                         request.Method,
                         PreflightHttpMethod,
                         StringComparison.Ordinal) &&
-                    accessControlRequestMethod != null)
+                    !StringValues.IsNullOrEmpty(accessControlRequestMethod))
                 {
                     method = accessControlRequestMethod;
                 }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormCollectionModelBinder.cs

@@ -8,6 +8,7 @@ using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
 using Microsoft.Framework.Internal;
+using Microsoft.Framework.Primitives;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
@@ -51,11 +52,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
         private class EmptyFormCollection : IFormCollection
         {
-            public string this[string key]
+            public StringValues this[string key]
             {
                 get
                 {
-                    return null;
+                    return StringValues.Empty;
                 }
             }
 
@@ -93,12 +94,12 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 return null;
             }
 
-            public IEnumerator<KeyValuePair<string, string[]>> GetEnumerator()
+            public IEnumerator<KeyValuePair<string, StringValues>> GetEnumerator()
             {
-                return Enumerable.Empty<KeyValuePair<string, string[]>>().GetEnumerator();
+                return Enumerable.Empty<KeyValuePair<string, StringValues>>().GetEnumerator();
             }
 
-            public IList<string> GetValues(string key)
+            public IList<StringValues> GetValues(string key)
             {
                 return null;
             }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/HeaderModelBinder.cs

@@ -2,11 +2,11 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
-using System.Linq;
 #if DNXCORE50
 using System.Reflection;
 #endif
 using System.Threading.Tasks;
+using Microsoft.AspNet.Http;
 using Microsoft.Framework.Internal;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
@@ -36,7 +36,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             object model = null;
             if (bindingContext.ModelType == typeof(string))
             {
-                var value = request.Headers.Get(headerName);
+                string value = request.Headers[headerName];
                 if (value != null)
                 {
                     model = value;
@@ -45,7 +45,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             else if (typeof(IEnumerable<string>).IsAssignableFrom(bindingContext.ModelType))
             {
                 var values = request.Headers.GetCommaSeparatedValues(headerName);
-                if (values != null)
+                if (values.Length > 0)
                 {
                     model = ModelBindingHelper.ConvertValuesToCollectionType(
                         bindingContext.ModelType,
@@ -60,11 +60,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                     bindingContext.ModelName,
                     bindingContext.ModelMetadata,
                     model);
-                
+
                 bindingContext.ModelState.SetModelValue(
-                    bindingContext.ModelName, 
+                    bindingContext.ModelName,
-                    request.Headers.GetCommaSeparatedValues(headerName).ToArray(), 
+                    request.Headers.GetCommaSeparatedValues(headerName),
-                    request.Headers.Get(headerName));
+                    request.Headers[headerName]);
             }
 
             return Task.FromResult(

src/Microsoft.AspNet.Mvc.Core/ModelBinding/JQueryFormValueProvider.cs

@@ -1,11 +1,12 @@
 // 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;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Globalization;
 using System.Threading.Tasks;
 using Microsoft.Framework.Internal;
+using Microsoft.Framework.Primitives;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
@@ -14,8 +15,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
     /// </summary>
     public class JQueryFormValueProvider : BindingSourceValueProvider, IEnumerableValueProvider
     {
+        private readonly IDictionary<string, StringValues> _values;
         private PrefixContainer _prefixContainer;
-        private readonly IDictionary<string, string[]> _values;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="DictionaryBasedValueProvider"/> class.
@@ -25,7 +26,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// <param name="culture">The culture to return with ValueProviderResult instances.</param>
         public JQueryFormValueProvider(
             [NotNull] BindingSource bindingSource,
-            [NotNull] IDictionary<string, string[]> values,
+            [NotNull] IDictionary<string, StringValues> values,
             CultureInfo culture)
             : base(bindingSource)
         {
@@ -64,8 +65,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// <inheritdoc />
         public override ValueProviderResult GetValue(string key)
         {
-            string[] values;
+            StringValues values;
-            if (_values.TryGetValue(key, out values) && values != null && values.Length > 0)
+            if (_values.TryGetValue(key, out values) && values.Count > 0)
             {
                 return new ValueProviderResult(values, Culture);
             }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/JQueryFormValueProviderFactory.cs

@@ -9,6 +9,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc.Core;
 using Microsoft.Framework.Internal;
+using Microsoft.Framework.Primitives;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
@@ -29,11 +30,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             return null;
         }
 
-        private static async Task<IDictionary<string, string[]>> GetValueCollectionAsync(HttpRequest request)
+        private static async Task<IDictionary<string, StringValues>> GetValueCollectionAsync(HttpRequest request)
         {
             var formCollection = await request.ReadFormAsync();
 
-            var dictionary = new Dictionary<string, string[]>(StringComparer.OrdinalIgnoreCase);
+            var dictionary = new Dictionary<string, StringValues>(StringComparer.OrdinalIgnoreCase);
             foreach (var entry in formCollection)
             {
                 var key = NormalizeJQueryToMvc(entry.Key);

src/Microsoft.AspNet.Mvc.Core/ModelBinding/ReadableStringCollectionValueProvider.cs

@@ -1,12 +1,8 @@
 // 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;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Globalization;
-using System.Linq;
-using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
 using Microsoft.Framework.Internal;
 
@@ -73,14 +69,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// <inheritdoc />
         public override ValueProviderResult GetValue([NotNull] string key)
         {
-            var values = _values.GetValues(key);
+            var values = _values[key];
-            if (values == null)
+            if (values.Count == 0)
             {
                 return ValueProviderResult.None;
             }
             else
             {
-                return new ValueProviderResult(values.ToArray(), _culture);
+                return new ValueProviderResult(values, _culture);
             }
         }
     }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/ValueProviderResultExtensions.cs

@@ -21,7 +21,15 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// </returns>
         public static T ConvertTo<T>(this ValueProviderResult result)
         {
-            var valueToConvert = (object)result.Values ?? (object)result.Value;
+            object valueToConvert = null;
+            if (result.Values.Count == 1)
+            {
+                valueToConvert = result.Values[0];
+            }
+            else if (result.Values.Count > 1)
+            {
+                valueToConvert = result.Values.ToArray();
+            }
             return ModelBindingHelper.ConvertTo<T>(valueToConvert, result.Culture);
         }
 
@@ -35,7 +43,15 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// </returns>
         public static object ConvertTo(this ValueProviderResult result, [NotNull] Type type)
         {
-            var valueToConvert = (object)result.Values ?? (object)result.Value;
+            object valueToConvert = null;
+            if (result.Values.Count == 1)
+            {
+                valueToConvert = result.Values[0];
+            }
+            else if (result.Values.Count > 1)
+            {
+                valueToConvert = result.Values.ToArray();
+            }
             return ModelBindingHelper.ConvertTo(valueToConvert, type, result.Culture);
         }
     }

src/Microsoft.AspNet.Mvc.Core/ResponseCacheFilter.cs

@@ -4,8 +4,10 @@
 using System;
 using System.Globalization;
 using System.Linq;
+using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc.Core;
 using Microsoft.Framework.Internal;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNet.Mvc
 {
@@ -94,24 +96,24 @@ namespace Microsoft.AspNet.Mvc
             var headers = context.HttpContext.Response.Headers;
 
             // Clear all headers
-            headers.Remove("Vary");
+            headers.Remove(HeaderNames.Vary);
-            headers.Remove("Cache-control");
+            headers.Remove(HeaderNames.CacheControl);
-            headers.Remove("Pragma");
+            headers.Remove(HeaderNames.Pragma);
 
             if (!string.IsNullOrEmpty(VaryByHeader))
             {
-                headers.Set("Vary", VaryByHeader);
+                headers[HeaderNames.Vary] = VaryByHeader;
             }
 
             if (NoStore)
             {
-                headers.Set("Cache-control", "no-store");
+                headers[HeaderNames.CacheControl] = "no-store";
 
                 // Cache-control: no-store, no-cache is valid.
                 if (Location == ResponseCacheLocation.None)
                 {
-                    headers.Append("Cache-control", "no-cache");
+                    headers.AppendCommaSeparatedValues(HeaderNames.CacheControl, "no-cache");
-                    headers.Set("Pragma", "no-cache");
+                    headers[HeaderNames.Pragma] = "no-cache";
                 }
             }
             else
@@ -127,7 +129,7 @@ namespace Microsoft.AspNet.Mvc
                         break;
                     case ResponseCacheLocation.None:
                         cacheControlValue = "no-cache";
-                        headers.Set("Pragma", "no-cache");
+                        headers[HeaderNames.Pragma] = "no-cache";
                         break;
                 }
 
@@ -140,7 +142,7 @@ namespace Microsoft.AspNet.Mvc
 
                 if (cacheControlValue != null)
                 {
-                    headers.Set("Cache-control", cacheControlValue);
+                    headers[HeaderNames.CacheControl] = cacheControlValue;
                 }
             }
         }

src/Microsoft.AspNet.Mvc.Cors/CorsAuthorizationFilter.cs

@@ -8,6 +8,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Cors.Core;
 using Microsoft.AspNet.Http;
 using Microsoft.Framework.Internal;
+using Microsoft.Framework.Primitives;
 
 namespace Microsoft.AspNet.Mvc
 {
@@ -20,7 +21,7 @@ namespace Microsoft.AspNet.Mvc
         private ICorsPolicyProvider _corsPolicyProvider;
 
         /// <summary>
-        /// Creates a new instace of <see cref="CorsAuthorizationFilter"/>.
+        /// Creates a new instance of <see cref="CorsAuthorizationFilter"/>.
         /// </summary>
         /// <param name="corsService">The <see cref="ICorsService"/>.</param>
         /// <param name="policyProvider">The <see cref="ICorsPolicyProvider"/>.</param>
@@ -63,12 +64,12 @@ namespace Microsoft.AspNet.Mvc
                 _corsService.ApplyResult(result, context.HttpContext.Response);
 
                 var accessControlRequestMethod = 
-                        httpContext.Request.Headers.Get(CorsConstants.AccessControlRequestMethod);
+                        httpContext.Request.Headers[CorsConstants.AccessControlRequestMethod];
                 if (string.Equals(
                         request.Method,
                         CorsConstants.PreflightHttpMethod,
                         StringComparison.Ordinal) &&
-                    accessControlRequestMethod != null)
+                    !StringValues.IsNullOrEmpty(accessControlRequestMethod))
                 {
                     // If this was a preflight, there is no need to run anything else.
                     // Also the response is always 200 so that anyone after mvc can handle the pre flight request.

src/Microsoft.AspNet.Mvc.Cors/DisableCorsAuthorizationFilter.cs

@@ -6,6 +6,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Cors.Core;
 using Microsoft.AspNet.Http;
 using Microsoft.Framework.Internal;
+using Microsoft.Framework.Primitives;
 
 namespace Microsoft.AspNet.Mvc
 {
@@ -27,12 +28,12 @@ namespace Microsoft.AspNet.Mvc
         public Task OnAuthorizationAsync([NotNull] AuthorizationContext context)
         {
             var accessControlRequestMethod = 
-                        context.HttpContext.Request.Headers.Get(CorsConstants.AccessControlRequestMethod);
+                        context.HttpContext.Request.Headers[CorsConstants.AccessControlRequestMethod];
             if (string.Equals(
                     context.HttpContext.Request.Method,
                     CorsConstants.PreflightHttpMethod,
                     StringComparison.Ordinal) &&
-                accessControlRequestMethod != null)
+                !StringValues.IsNullOrEmpty(accessControlRequestMethod))
             {
                 // Short circuit if the request is preflight as that should not result in action execution.
                 context.Result = new HttpStatusCodeResult(StatusCodes.Status200OK);

src/Microsoft.AspNet.Mvc.WebApiCompatShim/Formatters/HttpResponseMessageOutputFormatter.cs

@@ -5,6 +5,7 @@ using System;
 using System.Linq;
 using System.Net.Http;
 using System.Threading.Tasks;
+using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Features;
 using Microsoft.Net.Http.Headers;
 
@@ -53,7 +54,7 @@ namespace Microsoft.AspNet.Mvc.WebApiCompatShim
                 
                 foreach (var header in responseHeaders)
                 {
-                    response.Headers.AppendValues(header.Key, header.Value.ToArray());
+                    response.Headers.Append(header.Key, header.Value.ToArray());
                 }
 
                 if (responseMessage.Content != null)
@@ -67,7 +68,7 @@ namespace Microsoft.AspNet.Mvc.WebApiCompatShim
                     
                     foreach (var header in contentHeaders)
                     {
-                        response.Headers.AppendValues(header.Key, header.Value.ToArray());
+                        response.Headers.Append(header.Key, header.Value.ToArray());
                     }
 
                     await responseMessage.Content.CopyToAsync(response.Body);

src/Microsoft.AspNet.Mvc.WebApiCompatShim/HttpRequestMessage/HttpRequestMessageFeature.cs

@@ -1,6 +1,7 @@
 // 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.Collections.Generic;
 using System.Diagnostics;
 using System.Net.Http;
 using Microsoft.AspNet.Http;
@@ -58,9 +59,9 @@ namespace Microsoft.AspNet.Mvc.WebApiCompatShim
             {
                 // Every header should be able to fit into one of the two header collections.
                 // Try message.Headers first since that accepts more of them.
-                if (!message.Headers.TryAddWithoutValidation(header.Key, header.Value))
+                if (!message.Headers.TryAddWithoutValidation(header.Key, (IEnumerable<string>)header.Value))
                 {
-                    var added = message.Content.Headers.TryAddWithoutValidation(header.Key, header.Value);
+                    var added = message.Content.Headers.TryAddWithoutValidation(header.Key, (IEnumerable<string>)header.Value);
                     Debug.Assert(added);
                 }
             }

test/Microsoft.AspNet.Mvc.Abstractions.Test/ModelBinding/ValueProviderResultTest.cs

@@ -1,6 +1,7 @@
 // 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 Microsoft.Framework.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
@@ -15,12 +16,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             // Assert
             Assert.Equal(0, result.Length);
-            Assert.Null(result.Value);
             Assert.Empty(result.Values);
             Assert.Null(result.FirstValue);
             Assert.Equal(ValueProviderResult.None, result);
             Assert.Null((string)result);
-            Assert.Empty((string[])result);
+            Assert.Null((string[])result);
         }
 
         [Fact]
@@ -31,12 +31,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             // Assert
             Assert.Equal(0, result.Length);
-            Assert.Null(result.Value);
             Assert.Empty(result.Values);
             Assert.Null(result.FirstValue);
             Assert.Equal(ValueProviderResult.None, result);
             Assert.Null((string)result);
-            Assert.Empty((string[])result);
+            Assert.Null((string[])result);
         }
 
         [Fact]
@@ -47,10 +46,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             // Assert
             Assert.Equal(0, result.Length);
-            Assert.Null(result.Value);
             Assert.Empty(result.Values);
             Assert.Null(result.FirstValue);
             Assert.Equal(ValueProviderResult.None, result);
+            Assert.Equal(ValueProviderResult.None, new ValueProviderResult(new StringValues()));
             Assert.Null((string)result);
             Assert.Empty((string[])result);
         }
@@ -63,8 +62,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             // Assert
             Assert.Equal(1, result.Length);
-            Assert.Equal("Hi There", result.Value);
+            Assert.Equal("Hi There", result.Values);
-            Assert.Null(result.Values);
             Assert.Equal("Hi There", result.FirstValue);
             Assert.NotEqual(ValueProviderResult.None, result);
             Assert.Equal("Hi There", (string)result);
@@ -79,7 +77,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             // Assert
             Assert.Equal(2, result.Length);
-            Assert.Null(result.Value);
             Assert.Equal(new string[] { "Hi", "There" }, result.Values);
             Assert.Equal("Hi", result.FirstValue);
             Assert.NotEqual(ValueProviderResult.None, result);

test/Microsoft.AspNet.Mvc.Core.Test/CreatedAtActionResultTests.cs

@@ -70,7 +70,7 @@ namespace Microsoft.AspNet.Mvc
             var httpResponse = new Mock<HttpResponse>();
             httpResponse.SetupProperty(o => o.StatusCode);
             httpResponse.Setup(o => o.Headers).Returns(
-                new HeaderDictionary(new Dictionary<string, string[]>()));
+                new HeaderDictionary());
             httpResponse.SetupGet(o => o.Body).Returns(stream);
             return httpResponse.Object;
         }

test/Microsoft.AspNet.Mvc.Core.Test/CreatedResultTests.cs

@@ -53,7 +53,7 @@ namespace Microsoft.AspNet.Mvc
             var location = "/test/";
             var httpContext = GetHttpContext();
             var actionContext = GetActionContext(httpContext);
-            httpContext.Response.Headers.Set("Location", "/different/location/");
+            httpContext.Response.Headers["Location"] = "/different/location/";
             var result = new CreatedResult(location, "testInput");
 
             // Act

test/Microsoft.AspNet.Mvc.Core.Test/FormatFilterTest.cs

@@ -72,7 +72,7 @@ namespace Microsoft.AspNet.Mvc
 
             // Query contains xml    
             httpContext.Setup(c => c.Request.Query.ContainsKey("format")).Returns(true);
-            httpContext.Setup(c => c.Request.Query.Get("format")).Returns("xml");
+            httpContext.Setup(c => c.Request.Query["format"]).Returns("xml");
 
             // Routedata contains json
             var data = new RouteData();

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/CompositeValueProviderTest.cs

@@ -8,6 +8,7 @@ using System.Collections.Generic;
 using System.Globalization;
 #if DNX451
 using System.Threading.Tasks;
+using Microsoft.Framework.Primitives;
 using Moq;
 using Xunit;
 #endif
@@ -18,11 +19,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
     {
         protected override IEnumerableValueProvider GetEnumerableValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, string[]> values,
+            IDictionary<string, StringValues> values,
             CultureInfo culture)
         {
             var emptyValueProvider =
-                new JQueryFormValueProvider(bindingSource, new Dictionary<string, string[]>(), culture);
+                new JQueryFormValueProvider(bindingSource, new Dictionary<string, StringValues>(), culture);
             var valueProvider = new JQueryFormValueProvider(bindingSource, values, culture);
 
             return new CompositeValueProvider(new[] { emptyValueProvider, valueProvider });

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/DictionaryModelBinderTest.cs

@@ -8,6 +8,7 @@ using System.Globalization;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Internal;
+using Microsoft.Framework.Primitives;
 using Moq;
 using Xunit;
 
@@ -453,10 +454,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             string keyFormat,
             IDictionary<string, string> dictionary)
         {
-            // Convert to an IDictionary<string, string[]> then wrap it up.
+            // Convert to an IDictionary<string, StringValues> then wrap it up.
             var backingStore = dictionary.ToDictionary(
                 kvp => string.Format(keyFormat, kvp.Key),
-                kvp => new[] { kvp.Value });
+                kvp => (StringValues)kvp.Value);
             var stringCollection = new ReadableStringCollection(backingStore);
 
             return new ReadableStringCollectionValueProvider(

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/EnumerableValueProviderTest.cs

@@ -5,34 +5,35 @@ using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
 using System.Threading.Tasks;
+using Microsoft.Framework.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
     public abstract class EnumerableValueProviderTest
     {
-        private static readonly IDictionary<string, string[]> _backingStore = new Dictionary<string, string[]>
+        private static readonly IDictionary<string, StringValues> _backingStore = new Dictionary<string, StringValues>
         {
             { "some", new[] { "someValue1", "someValue2" } },
-            { "null_value", null },
+            { "null_value", StringValues.Empty },
             { "prefix.name", new[] { "someOtherValue" } },
-            { "prefix.null_value", null },
+            { "prefix.null_value", StringValues.Empty },
-            { "prefix.property1.property", null },
+            { "prefix.property1.property", StringValues.Empty },
-            { "prefix.property2[index]", null },
+            { "prefix.property2[index]", StringValues.Empty },
-            { "prefix[index1]", null },
+            { "prefix[index1]", StringValues.Empty },
-            { "prefix[index1].property1", null },
+            { "prefix[index1].property1", StringValues.Empty },
-            { "prefix[index1].property2", null },
+            { "prefix[index1].property2", StringValues.Empty },
-            { "prefix[index2].property", null },
+            { "prefix[index2].property", StringValues.Empty },
-            { "[index]", null },
+            { "[index]", StringValues.Empty },
-            { "[index].property", null },
+            { "[index].property", StringValues.Empty },
-            { "[index][anotherIndex]", null },
+            { "[index][anotherIndex]", StringValues.Empty },
         };
 
         [Fact]
         public void ContainsPrefix_WithEmptyCollection_ReturnsFalseForEmptyPrefix()
         {
             // Arrange
-            var backingStore = new Dictionary<string, string[]>();
+            var backingStore = new Dictionary<string, StringValues>();
             var valueProvider = GetEnumerableValueProvider(BindingSource.Query, backingStore, culture: null);
 
             // Act
@@ -209,7 +210,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         public void GetValue_NullMultipleValue()
         {
             // Arrange
-            var backingStore = new Dictionary<string, string[]>
+            var backingStore = new Dictionary<string, StringValues>
             {
                 { "key", new string[] { null, null, "value" } },
             };
@@ -278,7 +279,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
         private IBindingSourceValueProvider GetBindingSourceValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, string[]> values,
+            IDictionary<string, StringValues> values,
             CultureInfo culture)
         {
             var provider = GetEnumerableValueProvider(bindingSource, values, culture) as IBindingSourceValueProvider;
@@ -291,7 +292,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
         protected abstract IEnumerableValueProvider GetEnumerableValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, string[]> values,
+            IDictionary<string, StringValues> values,
             CultureInfo culture);
     }
 }

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormCollectionModelBinderTest.cs

@@ -9,6 +9,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Internal;
+using Microsoft.Framework.Primitives;
 using Moq;
 using Xunit;
 
@@ -20,10 +21,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         public async Task FormCollectionModelBinder_ValidType_BindSuccessful()
         {
             // Arrange
-            var formCollection = new FormCollection(new Dictionary<string, string[]>
+            var formCollection = new FormCollection(new Dictionary<string, StringValues>
             {
-                { "field1", new string[] { "value1" } },
+                { "field1", "value1" },
-                { "field2", new string[] { "value2" } }
+                { "field2", "value2" }
             });
             var httpContext = GetMockHttpContext(formCollection);
             var bindingContext = GetBindingContext(typeof(IFormCollection), httpContext);
@@ -48,10 +49,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         public async Task FormCollectionModelBinder_InvalidType_BindFails()
         {
             // Arrange
-            var formCollection = new FormCollection(new Dictionary<string, string[]>
+            var formCollection = new FormCollection(new Dictionary<string, StringValues>
             {
-                { "field1", new string[] { "value1" } },
+                { "field1", "value1" },
-                { "field2", new string[] { "value2" } }
+                { "field2", "value2" }
             });
             var httpContext = GetMockHttpContext(formCollection);
             var bindingContext = GetBindingContext(typeof(string), httpContext);
@@ -69,9 +70,9 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         public async Task FormCollectionModelBinder_FormCollectionConcreteType_BindFails()
         {
             // Arrange
-            var formCollection = new FormCollection(new Dictionary<string, string[]>
+            var formCollection = new FormCollection(new Dictionary<string, StringValues>
             {
-                { "field1", new string[] { "value1" } },
+                { "field1", "value1" },
                 { "field2", new string[] { "value2" } }
             });
             var httpContext = GetMockHttpContext(formCollection);
@@ -131,11 +132,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
         private class MyFormCollection : ReadableStringCollection, IFormCollection
         {
-            public MyFormCollection(IDictionary<string, string[]> store) : this(store, new FormFileCollection())
+            public MyFormCollection(IDictionary<string, StringValues> store) : this(store, new FormFileCollection())
             {
             }
 
-            public MyFormCollection(IDictionary<string, string[]> store, IFormFileCollection files) : base(store)
+            public MyFormCollection(IDictionary<string, StringValues> store, IFormFileCollection files) : base(store)
             {
                 Files = files;
             }

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormValueProviderFactoryTest.cs

@@ -6,6 +6,7 @@ using System.Collections.Generic;
 using System.Globalization;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Internal;
+using Microsoft.Framework.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding.Test
@@ -52,7 +53,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
 
             if (context.Request.HasFormContentType)
             {
-                context.Request.Form = new FormCollection(new Dictionary<string, string[]>());
+                context.Request.Form = new FormCollection(new Dictionary<string, StringValues>());
             }
 
             return new ValueProviderFactoryContext(

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderFactoryTest.cs

@@ -6,13 +6,14 @@ using System.Collections.Generic;
 using System.Globalization;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Internal;
+using Microsoft.Framework.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding.Test
 {
     public class JQueryFormValueProviderFactoryTest
     {
-        private static readonly IDictionary<string, string[]> _backingStore = new Dictionary<string, string[]>
+        private static readonly IDictionary<string, StringValues> _backingStore = new Dictionary<string, StringValues>
         {
             { "[]", new[] { "found" } },
             { "[]property1", new[] { "found" } },
@@ -115,14 +116,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
 
         private static ValueProviderFactoryContext CreateContext(
             string contentType,
-            IDictionary<string, string[]> formValues)
+            IDictionary<string, StringValues> formValues)
         {
             var context = new DefaultHttpContext();
             context.Request.ContentType = contentType;
 
             if (context.Request.HasFormContentType)
             {
-                context.Request.Form = new FormCollection(formValues ?? new Dictionary<string, string[]>());
+                context.Request.Form = new FormCollection(formValues ?? new Dictionary<string, StringValues>());
             }
 
             return new ValueProviderFactoryContext(

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderTest.cs

@@ -3,6 +3,7 @@
 
 using System.Collections.Generic;
 using System.Globalization;
+using Microsoft.Framework.Primitives;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
@@ -10,7 +11,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
     {
         protected override IEnumerableValueProvider GetEnumerableValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, string[]> values,
+            IDictionary<string, StringValues> values,
             CultureInfo culture)
         {
             return new JQueryFormValueProvider(bindingSource, values, culture);

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/ReadableStringCollectionValueProviderTest.cs

@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Globalization;
 using Microsoft.AspNet.Http.Internal;
+using Microsoft.Framework.Primitives;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
@@ -11,7 +12,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
     {
         protected override IEnumerableValueProvider GetEnumerableValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, string[]> values,
+            IDictionary<string, StringValues> values,
             CultureInfo culture)
         {
             var backingStore = new ReadableStringCollection(values);

test/Microsoft.AspNet.Mvc.Core.Test/ResponseCacheFilterTest.cs

@@ -27,7 +27,7 @@ namespace Microsoft.AspNet.Mvc
             cache.OnActionExecuting(context);
 
             // Assert
-            Assert.Equal("no-store", context.HttpContext.Response.Headers.Get("Cache-control"));
+            Assert.Equal("no-store", context.HttpContext.Response.Headers["Cache-control"]);
         }
 
         [Fact]
@@ -157,7 +157,7 @@ namespace Microsoft.AspNet.Mvc
             cache.OnActionExecuting(context);
 
             // Assert
-            Assert.Equal(output, context.HttpContext.Response.Headers.Get("Cache-control"));
+            Assert.Equal(output, context.HttpContext.Response.Headers["Cache-control"]);
         }
 
         public static IEnumerable<object[]> NoStoreData
@@ -205,7 +205,7 @@ namespace Microsoft.AspNet.Mvc
             cache.OnActionExecuting(context);
 
             // Assert
-            Assert.Equal(output, context.HttpContext.Response.Headers.Get("Cache-control"));
+            Assert.Equal(output, context.HttpContext.Response.Headers["Cache-control"]);
         }
 
         public static IEnumerable<object[]> VaryData
@@ -275,8 +275,8 @@ namespace Microsoft.AspNet.Mvc
             cache.OnActionExecuting(context);
 
             // Assert
-            Assert.Equal(varyOutput, context.HttpContext.Response.Headers.Get("Vary"));
+            Assert.Equal(varyOutput, context.HttpContext.Response.Headers["Vary"]);
-            Assert.Equal(cacheControlOutput, context.HttpContext.Response.Headers.Get("Cache-control"));
+            Assert.Equal(cacheControlOutput, context.HttpContext.Response.Headers["Cache-control"]);
         }
 
         [Fact]
@@ -294,8 +294,8 @@ namespace Microsoft.AspNet.Mvc
             cache.OnActionExecuting(context);
 
             // Assert
-            Assert.Equal("no-store,no-cache", context.HttpContext.Response.Headers.Get("Cache-control"));
+            Assert.Equal("no-store,no-cache", context.HttpContext.Response.Headers["Cache-control"]);
-            Assert.Equal("no-cache", context.HttpContext.Response.Headers.Get("Pragma"));
+            Assert.Equal("no-cache", context.HttpContext.Response.Headers["Pragma"]);
         }
 
         [Fact]
@@ -339,7 +339,7 @@ namespace Microsoft.AspNet.Mvc
             cache.OnActionExecuting(context);
 
             // Assert
-            Assert.Equal("public,max-age=20", context.HttpContext.Response.Headers.Get("Cache-control"));
+            Assert.Equal("public,max-age=20", context.HttpContext.Response.Headers["Cache-control"]);
         }
 
         [Fact]
@@ -359,7 +359,7 @@ namespace Microsoft.AspNet.Mvc
             cache.OnActionExecuting(context);
 
             // Assert
-            Assert.Equal("private,max-age=10", context.HttpContext.Response.Headers.Get("Cache-control"));
+            Assert.Equal("private,max-age=10", context.HttpContext.Response.Headers["Cache-control"]);
         }
 
         [Fact]
@@ -379,7 +379,7 @@ namespace Microsoft.AspNet.Mvc
             cache.OnActionExecuting(context);
 
             // Assert
-            Assert.Equal("public,max-age=10", context.HttpContext.Response.Headers.Get("Cache-control"));
+            Assert.Equal("public,max-age=10", context.HttpContext.Response.Headers["Cache-control"]);
         }
 
         [Fact]
@@ -399,7 +399,7 @@ namespace Microsoft.AspNet.Mvc
             cache.OnActionExecuting(context);
 
             // Assert
-            Assert.Equal("Test", context.HttpContext.Response.Headers.Get("Vary"));
+            Assert.Equal("Test", context.HttpContext.Response.Headers["Vary"]);
         }
 
         private ActionExecutingContext GetActionExecutingContext(List<IFilterMetadata> filters = null)

test/Microsoft.AspNet.Mvc.Core.Test/project.json

@@ -3,6 +3,7 @@
         "warningsAsErrors": "true"
     },
     "dependencies": {
+        "Microsoft.AspNet.Http": "1.0.0-*",
         "Microsoft.AspNet.Mvc": "6.0.0-*",
         "Microsoft.AspNet.Mvc.TestCommon": {
             "version": "6.0.0-*",

test/Microsoft.AspNet.Mvc.Cors.Test/CorsAuthorizationFilterTest.cs

@@ -186,10 +186,9 @@ namespace Microsoft.AspNet.Mvc.Test
                 .Callback<CorsResult, HttpResponse>((result1, response1) =>
                 {
                     var headers = response1.Headers;
-                    headers.Set(
+                    headers[CorsConstants.AccessControlMaxAge] =
-                        CorsConstants.AccessControlMaxAge,
+                        result1.PreflightMaxAge.Value.TotalSeconds.ToString();
-                        result1.PreflightMaxAge.Value.TotalSeconds.ToString());
+                    headers[CorsConstants.AccessControlAllowOrigin] = result1.AllowedOrigin;
-                    headers.Add(CorsConstants.AccessControlAllowOrigin, new[] { result1.AllowedOrigin });
                     if (result1.SupportsCredentials)
                     {
                         headers.Add(CorsConstants.AccessControlAllowCredentials, new[] { "true" });

test/Microsoft.AspNet.Mvc.Cors.Test/project.json

@@ -3,6 +3,7 @@
         "warningsAsErrors": "true"
     },
     "dependencies": {
+        "Microsoft.AspNet.Http": "1.0.0-*",
         "Microsoft.AspNet.Mvc": "6.0.0-*",
         "Microsoft.AspNet.Mvc.Formatters.Xml" : "6.0.0-*",
         "Microsoft.AspNet.Mvc.TestCommon": { "version": "6.0.0-*", "type": "build" },

test/Microsoft.AspNet.Mvc.Formatters.Json.Test/project.json

@@ -3,6 +3,7 @@
         "warningsAsErrors": "true"
     },
     "dependencies": {
+        "Microsoft.AspNet.Http": "1.0.0-*",
         "Microsoft.AspNet.Mvc": "6.0.0-*",
         "Microsoft.AspNet.Mvc.Formatters.Xml": "6.0.0-*",
         "Microsoft.AspNet.Mvc.TestCommon": { "version": "6.0.0-*", "type": "build" },

test/Microsoft.AspNet.Mvc.Formatters.Xml.Test/XmlDataContractSerializerOutputFormatterTest.cs

@@ -621,7 +621,7 @@ namespace Microsoft.AspNet.Mvc.Formatters.Xml
         {
             var request = new Mock<HttpRequest>();
 
-            var headers = new HeaderDictionary(new Dictionary<string, string[]>(StringComparer.OrdinalIgnoreCase));
+            var headers = new HeaderDictionary();
             headers["Accept-Charset"] = MediaTypeHeaderValue.Parse(contentType).Charset;
             request.Setup(r => r.ContentType).Returns(contentType);
             request.SetupGet(r => r.Headers).Returns(headers);

test/Microsoft.AspNet.Mvc.Formatters.Xml.Test/XmlSerializerOutputFormatterTest.cs

@@ -375,7 +375,7 @@ namespace Microsoft.AspNet.Mvc.Formatters.Xml
         {
             var request = new Mock<HttpRequest>();
 
-            var headers = new HeaderDictionary(new Dictionary<string, string[]>(StringComparer.OrdinalIgnoreCase));
+            var headers = new HeaderDictionary();
             headers["Accept-Charset"] = MediaTypeHeaderValue.Parse(contentType).Charset;
             request.Setup(r => r.ContentType).Returns(contentType);
             request.SetupGet(r => r.Headers).Returns(headers);

test/Microsoft.AspNet.Mvc.Formatters.Xml.Test/project.json

@@ -3,6 +3,7 @@
     "warningsAsErrors": "true"
   },
   "dependencies": {
+    "Microsoft.AspNet.Http": "1.0.0-*",
     "Microsoft.AspNet.Mvc" : "6.0.0-*",
     "Microsoft.AspNet.Mvc.Formatters.Xml" : "6.0.0-*",
     "Microsoft.AspNet.Testing": "1.0.0-*",

test/Microsoft.AspNet.Mvc.FunctionalTests/FiltersTest.cs

@@ -68,12 +68,12 @@ namespace Microsoft.AspNet.Mvc.FunctionalTests
 
             var body = await response.Content.ReadAsStringAsync();
 
-            var filters = response.Headers.GetValues("filters").Single().Split(',');
+            var filters = response.Headers.GetValues("filters").ToArray();
 
             var i = 0;
             foreach (var filter in filters)
             {
-                Assert.Equal(filter, expected[i++]);
+                Assert.Equal(expected[i++], filter);
             }
 
             Assert.Equal(expected.Length, filters.Length);

test/Microsoft.AspNet.Mvc.IntegrationTests/CollectionModelBinderIntegrationTest.cs

@@ -10,6 +10,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.ModelBinding;
+using Microsoft.Framework.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.IntegrationTests
@@ -604,7 +605,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
             var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
             {
-                var formCollection = new FormCollection(new Dictionary<string, string[]>()
+                var formCollection = new FormCollection(new Dictionary<string, StringValues>()
                 {
                     { "Addresses.index", new [] { "Key1", "Key2" } },
                     { "Addresses[Key1].Street", new [] { "Street1" } },
@@ -663,7 +664,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
             var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
             {
-                var formCollection = new FormCollection(new Dictionary<string, string[]>()
+                var formCollection = new FormCollection(new Dictionary<string, StringValues>()
                 {
                     { "Addresses.index", new [] { "Key1" } },
                     { "Addresses[Key1].Street", new [] { "Street1" } },
@@ -733,15 +734,15 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
         }
 
         // parameter type, form content, expected type
-        public static TheoryData<Type, IDictionary<string, string[]>, Type> CollectionTypeData
+        public static TheoryData<Type, IDictionary<string, StringValues>, Type> CollectionTypeData
         {
             get
             {
-                return new TheoryData<Type, IDictionary<string, string[]>, Type>
+                return new TheoryData<Type, IDictionary<string, StringValues>, Type>
                 {
                     {
                         typeof(IEnumerable<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[0]", new[] { "hello" } },
                             { "[1]", new[] { "world" } },
@@ -750,7 +751,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ICollection<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "index", new[] { "low", "high" } },
                             { "[low]", new[] { "hello" } },
@@ -760,7 +761,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(IList<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[0]", new[] { "hello" } },
                             { "[1]", new[] { "world" } },
@@ -769,7 +770,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(List<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "index", new[] { "low", "high" } },
                             { "[low]", new[] { "hello" } },
@@ -779,7 +780,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ClosedGenericCollection),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[0]", new[] { "hello" } },
                             { "[1]", new[] { "world" } },
@@ -788,7 +789,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ClosedGenericList),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "index", new[] { "low", "high" } },
                             { "[low]", new[] { "hello" } },
@@ -798,7 +799,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ExplicitClosedGenericCollection),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[0]", new[] { "hello" } },
                             { "[1]", new[] { "world" } },
@@ -807,7 +808,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ExplicitClosedGenericList),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "index", new[] { "low", "high" } },
                             { "[low]", new[] { "hello" } },
@@ -817,7 +818,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ExplicitCollection<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[0]", new[] { "hello" } },
                             { "[1]", new[] { "world" } },
@@ -826,7 +827,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ExplicitList<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "index", new[] { "low", "high" } },
                             { "[low]", new[] { "hello" } },
@@ -836,7 +837,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(IEnumerable<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { string.Empty, new[] { "hello", "world" } },
                         },
@@ -844,7 +845,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ICollection<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[]", new[] { "hello", "world" } },
                         },
@@ -852,7 +853,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(IList<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { string.Empty, new[] { "hello", "world" } },
                         },
@@ -860,7 +861,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(List<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[]", new[] { "hello", "world" } },
                         },
@@ -868,7 +869,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ClosedGenericCollection),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { string.Empty, new[] { "hello", "world" } },
                         },
@@ -876,7 +877,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ClosedGenericList),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[]", new[] { "hello", "world" } },
                         },
@@ -884,7 +885,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ExplicitClosedGenericCollection),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { string.Empty, new[] { "hello", "world" } },
                         },
@@ -892,7 +893,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ExplicitClosedGenericList),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[]", new[] { "hello", "world" } },
                         },
@@ -900,7 +901,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ExplicitCollection<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { string.Empty, new[] { "hello", "world" } },
                         },
@@ -908,7 +909,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
                     },
                     {
                         typeof(ExplicitList<string>),
-                        new Dictionary<string, string[]>
+                        new Dictionary<string, StringValues>
                         {
                             { "[]", new[] { "hello", "world" } },
                         },
@@ -922,7 +923,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
         [MemberData(nameof(CollectionTypeData))]
         public async Task CollectionModelBinder_BindsParameterToExpectedType(
             Type parameterType,
-            IDictionary<string, string[]> formContent,
+            IDictionary<string, StringValues> formContent,
             Type expectedType)
         {
             // Arrange

test/Microsoft.AspNet.Mvc.IntegrationTests/FormCollectionModelBindingIntegrationTest.cs

@@ -9,6 +9,7 @@ using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Features.Internal;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.ModelBinding;
+using Microsoft.Framework.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.IntegrationTests
@@ -163,7 +164,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
         private void UpdateRequest(HttpRequest request, string data, string name)
         {
             var fileCollection = new FormFileCollection();
-            var formCollection = new FormCollection(new Dictionary<string, string[]>(), fileCollection);
+            var formCollection = new FormCollection(new Dictionary<string, StringValues>(), fileCollection);
             var memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(data));
 
             request.Form = formCollection;

test/Microsoft.AspNet.Mvc.IntegrationTests/FormFileModelBindingIntegrationTest.cs

@@ -9,6 +9,7 @@ using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Features.Internal;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.ModelBinding;
+using Microsoft.Framework.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.IntegrationTests
@@ -164,7 +165,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
         private void UpdateRequest(HttpRequest request, string data, string name)
         {
             var fileCollection = new FormFileCollection();
-            var formCollection = new FormCollection(new Dictionary<string, string[]>(), fileCollection);
+            var formCollection = new FormCollection(new Dictionary<string, StringValues>(), fileCollection);
 
             request.Form = formCollection;
             request.ContentType = "multipart/form-data; boundary=----WebKitFormBoundarymx2fSWqWSd0OxQqq";

test/Microsoft.AspNet.Mvc.IntegrationTests/MutableObjectModelBinderIntegrationTest.cs

@@ -10,6 +10,7 @@ using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Features.Internal;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.ModelBinding;
+using Microsoft.Framework.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.IntegrationTests
@@ -2129,7 +2130,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
         private static void SetFormFileBodyContent(HttpRequest request, string content, string name)
         {
             var fileCollection = new FormFileCollection();
-            var formCollection = new FormCollection(new Dictionary<string, string[]>(), fileCollection);
+            var formCollection = new FormCollection(new Dictionary<string, StringValues>(), fileCollection);
             var memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(content));
 
             request.Form = formCollection;

test/Microsoft.AspNet.Mvc.IntegrationTests/SimpleTypeModelBinderIntegrationTest.cs

@@ -9,6 +9,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.ModelBinding;
+using Microsoft.Framework.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.IntegrationTests
@@ -366,19 +367,19 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             Assert.Empty(modelState.Keys);
         }
 
-        public static TheoryData<IDictionary<string, string[]>> PersonStoreData
+        public static TheoryData<IDictionary<string, StringValues>> PersonStoreData
         {
             get
             {
-                return new TheoryData<IDictionary<string, string[]>>
+                return new TheoryData<IDictionary<string, StringValues>>
                 {
-                    new Dictionary<string, string[]>
+                    new Dictionary<string, StringValues>
                     {
                         { "name", new[] { "Fred" } },
                         { "address.zip", new[] { "98052" } },
                         { "address.lines", new[] { "line 1", "line 2" } },
                     },
-                    new Dictionary<string, string[]>
+                    new Dictionary<string, StringValues>
                     {
                         { "address.lines[]", new[] { "line 1", "line 2" } },
                         { "address[].zip", new[] { "98052" } },
@@ -390,7 +391,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
         [Theory]
         [MemberData(nameof(PersonStoreData))]
-        public async Task BindParameter_FromFormData_BindsCorrectly(IDictionary<string, string[]> personStore)
+        public async Task BindParameter_FromFormData_BindsCorrectly(IDictionary<string, StringValues> personStore)
         {
             // Arrange
             var argumentBinder = ModelBindingTestHelper.GetArgumentBinder();

test/Microsoft.AspNet.Mvc.IntegrationTests/project.json

@@ -3,6 +3,7 @@
         "warningsAsErrors": "true"
     },
     "dependencies": {
+        "Microsoft.AspNet.Http": "1.0.0-*",
         "Microsoft.AspNet.Mvc": "6.0.0-*",
         "Microsoft.AspNet.Mvc.Formatters.Xml": "6.0.0-*",
         "Microsoft.AspNet.Mvc.TestCommon": {

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/project.json

@@ -3,6 +3,7 @@
         "warningsAsErrors": "true"
     },
     "dependencies": {
+        "Microsoft.AspNet.Http": "1.0.0-*",
         "Microsoft.AspNet.Mvc": "6.0.0-*",
         "Microsoft.AspNet.Mvc.Formatters.Xml": "6.0.0-*",
         "Microsoft.AspNet.Mvc.TestCommon": { "version": "6.0.0-*", "type": "build" },

test/Microsoft.AspNet.Mvc.WebApiCompatShimTest/HttpResponseMessageOutputFormatterTests.cs

@@ -113,7 +113,7 @@ namespace Microsoft.AspNet.Mvc.WebApiCompatShimTest
             // Assert
             Assert.True(httpContext.Response.Headers.ContainsKey(transferEncodingHeaderKey));
             Assert.Equal(new string[] { "identity", "chunked" }, 
-                        httpContext.Response.Headers.GetValues(transferEncodingHeaderKey));
+                        httpContext.Response.Headers[transferEncodingHeaderKey]);
             Assert.NotNull(httpContext.Response.ContentLength);
         }
 
@@ -141,7 +141,7 @@ namespace Microsoft.AspNet.Mvc.WebApiCompatShimTest
             // Assert
             Assert.True(httpContext.Response.Headers.ContainsKey(transferEncodingHeaderKey));
             Assert.Equal(new string[] { "identity", "chunked" },
-                        httpContext.Response.Headers.GetValues(transferEncodingHeaderKey));
+                        httpContext.Response.Headers[transferEncodingHeaderKey]);
             Assert.NotNull(httpContext.Response.ContentLength);
         }
 

test/WebSites/CustomRouteWebSite/LocalizedRoute.cs

@@ -63,7 +63,7 @@ namespace CustomRouteWebSite
         private string GetLocale(HttpContext context)
         {
             string locale;
-            _users.TryGetValue(context.Request.Headers.Get("User"), out locale);
+            _users.TryGetValue(context.Request.Headers["User"], out locale);
             return locale;
         }
     }

test/WebSites/FiltersWebSite/Controllers/ProductsController.cs

@@ -1,6 +1,7 @@
 // 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 Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/AuthorizeUserAttribute.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Security.Claims;
+using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/ControllerActionFilter.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
+using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/ControllerAuthorizationFilter.cs

@@ -1,6 +1,7 @@
 // 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 Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/ControllerResultFilter.cs

@@ -1,6 +1,7 @@
 // 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 Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/GlobalActionFilter.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
+using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/GlobalAuthorizationFilter.cs

@@ -1,6 +1,7 @@
 // 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 Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/GlobalResultFilter.cs

@@ -1,6 +1,7 @@
 // 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 Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/PassThroughActionFilter.cs

@@ -1,6 +1,7 @@
 // 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 Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/PassThroughResultFilter.cs

@@ -1,6 +1,7 @@
 // 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 Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/FiltersWebSite/Filters/TracingResourceFilter.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 
 namespace FiltersWebSite

test/WebSites/LoggingWebSite/Models/RequestInfoDto.cs

@@ -1,6 +1,5 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
+using Microsoft.Framework.Primitives;
-using Microsoft.AspNet.Http;
 
 namespace LoggingWebSite
 {
@@ -22,10 +21,10 @@ namespace LoggingWebSite
 
         public string Protocol { get; set; }
 
-        public IEnumerable<KeyValuePair<string, string[]>> Headers { get; set; }
+        public IEnumerable<KeyValuePair<string, StringValues>> Headers { get; set; }
 
         public string Query { get; set; }
 
-        public IEnumerable<KeyValuePair<string, string[]>> Cookies { get; set; }
+        public IEnumerable<KeyValuePair<string, StringValues>> Cookies { get; set; }
     }
 }

test/WebSites/ModelBindingWebSite/Controllers/ModelBinderAttribute_ProductController.cs

@@ -73,7 +73,7 @@ namespace ModelBindingWebSite.Controllers
                     // Doing something slightly different here to make sure we don't get accidentally bound
                     // by the type converter binder.
                     OrderStatus model;
-                    var isModelSet = Enum.TryParse<OrderStatus>("Status" + request.Query.Get("status"), out model);
+                    var isModelSet = Enum.TryParse<OrderStatus>("Status" + request.Query["status"], out model);
                     var validationNode =
                      new ModelValidationNode(bindingContext.ModelName, bindingContext.ModelMetadata, model);
                     return Task.FromResult(new ModelBindingResult(model, "status", isModelSet, validationNode));

test/WebSites/ModelBindingWebSite/Controllers/TryUpdateModelController.cs

@@ -10,6 +10,7 @@ using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc;
 using Microsoft.AspNet.Mvc.ModelBinding;
+using Microsoft.Framework.Primitives;
 using ModelBindingWebSite.Models;
 
 namespace ModelBindingWebSite.Controllers
@@ -107,7 +108,7 @@ namespace ModelBindingWebSite.Controllers
         public async Task<Employee> GetEmployeeAsync_BindToBaseDeclaredType()
         {
             var backingStore = new ReadableStringCollection(
-            new Dictionary<string, string[]>
+            new Dictionary<string, StringValues>
             {
                 { "Parent.Name", new[] { "fatherName"} },
                 { "Parent.Parent.Name", new[] {"grandFatherName" } },
@@ -131,7 +132,7 @@ namespace ModelBindingWebSite.Controllers
         public async Task<User> GetUserAsync_ModelType_IncludeAll(int id)
         {
             var backingStore = new ReadableStringCollection(
-            new Dictionary<string, string[]>
+            new Dictionary<string, StringValues>
             {
                 { "Key", new[] { "123"} },
                 { "RegisterationMonth", new[] {"March" } },

test/WebSites/ResponseCacheWebSite/Controllers/CacheHeadersController.cs

@@ -46,7 +46,7 @@ namespace ResponseCacheWebSite
         [ResponseCache(Duration = 40)]
         public IActionResult SetHeadersInAction()
         {
-            Response.Headers.Set("Cache-control", "max-age=10");
+            Response.Headers["Cache-control"] = "max-age=10";
             return Content("Hello World!");
         }
 

test/WebSites/VersioningWebSite/VersionRangeValidator.cs

@@ -21,7 +21,7 @@ namespace VersioningWebSite
 
         public static string GetVersion(HttpRequest request)
         {
-            return request.Query.Get("version");
+            return request.Query["version"];
         }
 
         public bool Accept(ActionConstraintContext context)