@helper AddFlashUploader(
                string uploadUrl,
                string queryParameters,
                string flashUrl,
                int totalUploadSizeLimit = 0,
                int uploadFileSizeLimit = 0,
                string fileTypes = "",
                string fileTypeDescription = "",
                string onUploadComplete = "")
    {      
        onUploadComplete = string.IsNullOrEmpty(onUploadComplete) ? "" : "completeFunction=" + onUploadComplete;
        queryParameters = Server.UrlEncode(queryParameters);        
        fileTypes = string.IsNullOrEmpty(fileTypes) ? "" : "&fileTypes=" + Server.UrlEncode(fileTypes);
        fileTypeDescription = string.IsNullOrEmpty(fileTypeDescription) ? "" : "&fileTypeDescription=" + Server.UrlEncode(fileTypeDescription);
        var totalUploadSizeLimitData = totalUploadSizeLimit > 0 ? "&totalUploadSize=" + totalUploadSizeLimit : "";
        var uploadFileSizeLimitData = uploadFileSizeLimit > 0 ? "&fileSizeLimit=" + uploadFileSizeLimit : "";
        var flashVars = onUploadComplete + fileTypes + fileTypeDescription + totalUploadSizeLimitData + uploadFileSizeLimitData + "&uploadPage=" + uploadUrl + "?" + queryParameters;
    <object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0"
        width="575" height="375" id="fileUpload" align="middle">
        <param name="allowScriptAccess" value="sameDomain" />
        <param name="movie" value="@flashUrl" />
        <param name="quality" value="high" />
        <param name="wmode" value="transparent">
        <param name=FlashVars value="@flashVars">
        <embed src="@flashUrl"
               FlashVars="@flashVars" 
               quality="high" 
               wmode="transparent" 
               width="575" 
               height="375" 
               name="fileUpload" 
               align="middle" 
               allowScriptAccess="sameDomain" 
               type="application/x-shockwave-flash" 
               pluginspage="http://www.macromedia.com/go/getflashplayer" />
    </object>                        
}

@{
    ViewBag.Title = "Index";
    var uploadUrl = Url.Action("Uploader", "Home");
    var flashUrl = Url.Content("~/Content/FlashUpload/FlashFileUpload.swf");
}
<h2>
    Flash Uploader</h2>
<div style="background: #E0EBEF;">
    @FlashUploadHelper.AddFlashUploader(
                uploadUrl: uploadUrl,
                queryParameters: "User=Vahid&Id=تست",
                flashUrl: flashUrl,
                fileTypeDescription: "Images",
                fileTypes: "*.gif; *.png; *.jpg; *.jpeg",
                uploadFileSizeLimit: 0,
                totalUploadSizeLimit: 0,
                onUploadComplete: "alert('انجام شد');")
</div>

using System.Collections.Generic;
using System.IO;
using System.Web;
using System.Web.Mvc;

namespace MvcFlashUpload.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            return View();
        }

        public ActionResult Uploader(string User, string Id, IEnumerable<HttpPostedFileBase> FileData)
        {
            var queryParameter1 = User;
            var queryParameter2 = Id;
            // ...

            foreach (var file in FileData)
            {
                if (file.ContentLength > 0)
                {
                    var fileName = Path.GetFileName(file.FileName);
                    var path = Path.Combine(Server.MapPath("~/App_Data/Uploads"), fileName);
                    file.SaveAs(path);
                }
            }

            return Content(" ");
        }
    }
}