JsonResult that uses Newtonsoft.JSON.Net for WebAPI

JsonNetResult.cs

using System;
using System.IO;
using System.Text;
using System.Web.Mvc;
using Newtonsoft.Json;

namespace XXX
{
    public class JsonNetResult<T> : ActionResult
    {
        private JsonSerializerSettings _jsonSerializerSettings;
        public T Content { get; }
        public Encoding Encoding { get; }

        public JsonNetResult(T content, JsonSerializerSettings jsonSerializerSettings, Encoding encoding)
        {
            if (encoding == null)
                throw new ArgumentNullException(nameof(encoding));
            Content = content;
            _jsonSerializerSettings = jsonSerializerSettings;
            Encoding = encoding;
        }

        public override void ExecuteResult(ControllerContext context)
        {
            if (context == null)
                throw new ArgumentNullException(nameof(context));
            var response = context.HttpContext.Response;
            response.ContentType = "application/json";
            response.ContentEncoding = Encoding;
            if (Content == null)
                return;
            var responseBytes = Serialize();
            response.OutputStream.Write(responseBytes.Array, responseBytes.Offset, responseBytes.Count);
        }

        private ArraySegment<byte> Serialize()
        {
            var jsonSerializer = JsonSerializer.Create(_jsonSerializerSettings);
            using (var memoryStream = new MemoryStream())
            {
                using (TextWriter textWriter = new StreamWriter(memoryStream, Encoding, 1024, true))
                {
                    var jsonTextWriter = new JsonTextWriter(textWriter)
                    {
                        CloseOutput = false
                    };
                    using (JsonWriter jsonWriter = jsonTextWriter)
                    {
                        jsonSerializer.Serialize(jsonWriter, Content);
                        jsonWriter.Flush();
                    }
                }
                return new ArraySegment<byte>(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);
            }
        }
    }
}

MvcControllerExtensions.cs

using System.Text;
using System.Web.Mvc;
using Newtonsoft.Json;

namespace XXX
{
    public static class MvcControllerExtensions
    {
        /// <summary>Creates a <see cref="T:XXX.JsonNetResult`1" /> (200 OK) with the specified value.</summary>
        /// <returns>A <see cref="T:XXX.JsonNetResult`1" /> with the specified value.</returns>
        /// <param name="controller">Controller that executes an action</param>
        /// <param name="content">The content value to serialize in the entity body.</param>
        /// <typeparam name="T">The type of content in the entity body.</typeparam>
        public static JsonNetResult<T> JsonNet<T>(this Controller controller, T content) => controller.JsonNet(content, new JsonSerializerSettings());

        /// <summary>Creates a <see cref="T:XXX.JsonNetResult`1" /> (200 OK) with the specified values.</summary>
        /// <returns>A <see cref="T:XXX.JsonNetResult`1" /> with the specified values.</returns>
        /// <param name="controller">Controller that executes an action</param>
        /// <param name="content">The content value to serialize in the entity body.</param>
        /// <param name="serializerSettings">The serializer settings.</param>
        /// <typeparam name="T">The type of content in the entity body.</typeparam>
        public static JsonNetResult<T> JsonNet<T>(this Controller controller, T content, JsonSerializerSettings serializerSettings) => controller.JsonNet<T>(content, serializerSettings, new UTF8Encoding(false, true));

        /// <summary>Creates a <see cref="T:XXX.JsonNetResult`1" /> (200 OK) with the specified values.</summary>
        /// <returns>A <see cref="T:XXX.JsonNetResult`1" /> with the specified values.</returns>
        /// <param name="controller">Controller that executes an action</param>
        /// <param name="content">The content value to serialize in the entity body.</param>
        /// <param name="serializerSettings">The serializer settings.</param>
        /// <param name="encoding">The content encoding.</param>
        /// <typeparam name="T">The type of content in the entity body.</typeparam>
        public static JsonNetResult<T> JsonNet<T>(this Controller controller, T content, JsonSerializerSettings serializerSettings, Encoding encoding) => new JsonNetResult<T>(content, serializerSettings, encoding);
    }
}