问Ajax.BeginForm PartialView未刷新

EN

private static int folderId = 0;

public ActionResult Index(int id)
{
    folderId = id;
    this.GetFiles();
    return PartialView();
}

public PartialViewResult FileList()
{
    this.GetFiles();
    return PartialView("FileList");
}

[HttpPost]
[ValidateAntiForgeryToken]
public PartialViewResult UploadFiles(IEnumerable<HttpPostedFileBase> filesToUpload)
{
        this.UploadFilesToBase(filesToUpload, 1);

    this.GetFiles();

    return PartialView("FileList");
}

 <script src="@Url.Content("~/Scripts/jquery-1.8.2.min.js")" type="text/javascript"></script>
 <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")" type="text/javascript"></script>
 <script src="@Url.Content("~/Scripts/modernizr-2.6.2.js")" type="text/javascript"></script>
 <script src="@Url.Content("~/Scripts/main.js")" type="text/javascript"></script>

 <script src="http://malsup.github.com/jquery.form.js"></script>
 <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7/jquery.js"></script>

@using (Ajax.BeginForm("UploadFiles", "File", null, new AjaxOptions { HttpMethod =             "POST", UpdateTargetId = "FilesListDiv", InsertionMode = InsertionMode.Replace }, new { enctype = "multipart/form-data" }))
{
   <div class="btn-upload-file">
      @Html.AntiForgeryToken()
      <span class="btn"><span>Upload file</span></span>
      <input type="file" class="file" name="filesToUpload" multiple    onchange="javascript:this.form.submit();"><br>
    </div>

 }

<div id="FilesListDiv">
   @*@Html.Action("FileList", "File")*@    
   @Html.Partial("~/Views/File/FileList.cshtml")
</div>

 @{
    Layout = null;
    ViewBag.Title = "Files";
 }

 @foreach (MyProj.Web.DataContracts.File file in ViewBag.Files)
 {         
    file.Name
 }