Not able to upload file using Ajax.BeginForm() asynchronously

I'm trying to upload a file using Ajax.BeginForm(), but it's not working out.

My view contains:

@using (Ajax.BeginForm("UploadFile", null, new AjaxOptions { HttpMethod="POST",     UpdateTargetId = "result" }, new { enctype = "multipart/form-data" }))
{
   <label id="lblUploadNewFile" for="fileUploadControl">Upload New File&lt;/label>
   <input type="file" name="fileToUpload" id="fileUploadControl"/>
   <input id="btnFileUpload" type="submit" value="Upload" />
   <span id="result" />
}

and the corresponding Controller is:

[HttpPost]
public string UploadFile(FormCollection formData)
{
   HttpPostedFileBase file=null;

   try
   {
      file = Request.Files[0];
   }
   catch { }

   if ( file!=null && file.ContentLength > 0)
   {
      file.SaveAs(string.Concat(
            AppDomain.CurrentDomain.BaseDirectory,
            Path.GetFileName(file.FileName)));

      return "Successfully Uploaded";
   }
   else
   {
      return "Upload Failed, please try again.";
   }
}

The problem is that it's uploading the file, but no longer doing any asynchronous posts when I remove jquery.unobtrusive-ajax.js. Instead, it does a full post-back.

When I add jquery.unobtrusive-ajax.js in my view, it's doing it asynchronously, but it is not sending an upload file in the form data. No file is being sent to the server in Request.Files[].

You cannot upload files using AJAX. This is not supported. If you want to do that you could either use some file upload plugin such as Uploadify or Blueimp File Upload or use the HTML 5 File API if the client browser supports it.

You can do this without additional libraries.

I came across this little hack, which resolves it nicely

window.addEventListener("submit", function (e) {
    var form = e.target;
    if (form.getAttribute("enctype") === "multipart/form-data") {
        if (form.dataset.ajax) {
            e.preventDefault();
            e.stopImmediatePropagation();
            var xhr = new XMLHttpRequest();
            xhr.open(form.method, form.action);
            xhr.onreadystatechange = function () {
                if (xhr.readyState == 4 && xhr.status == 200) {
                    if (form.dataset.ajaxUpdate) {
                        var updateTarget = document.querySelector(form.dataset.ajaxUpdate);
                        if (updateTarget) {
                            updateTarget.innerHTML = xhr.responseText;
                        } 
                    }
                }
            };
            xhr.send(new FormData(form));
        }
    }
}, true);

Found http://www.acnenomor.com/1762557p1/c-mvc3-ajaxbeginform-to-upload-file-not-working