ASP.Net MVC 5 FileContentResult that handles IE8. Can't claim credit for this. Putting here for anyone to use

FileResultThatHandlesIE8.cs

using System;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace AshleyGrant.Web
{
    public class FileResultThatHandlesIE8 : FileContentResult
    {
        private readonly string _fileName;
        public FileResultThatHandlesIE8(byte[] fileContents, string contentType, string fileName = null)
            : base(fileContents, contentType)
        {
            _fileName = fileName;
        }

        public override void ExecuteResult(ControllerContext context)
        {
            if (_fileName != null && String.IsNullOrWhiteSpace(base.FileDownloadName))
                base.FileDownloadName = _fileName;

            var b = context.HttpContext.Request.Browser;
            if (b != null && b.Browser.Equals("ie", StringComparison.OrdinalIgnoreCase) && b.MajorVersion <= 8)
            {
                context.HttpContext.Response.AppendHeader("Content-Disposition", "attachment; filename=\"" + HttpUtility.UrlPathEncode(base.FileDownloadName) + "\"");
                WriteFile(context.HttpContext.Response);
            }
            else
            {
                base.ExecuteResult(context);
            }
        }
    }
}

usage

// in any action simply use this like a normal FileResult
return new FileResultThatHandlesIE8(bytes, mimeType, fileName);