上傳檔案 透過 Ajax To Ashx

Script: 

<script type="text/javascript">
$(document).ready(function () {
  $("#Button1").click(function (evt) {
    var fileUpload = $("#FileUpload1").get(0);
    var files = fileUpload.files;

    var data = new FormData();
    for (var i = 0; i < files.length; i++) {
      data.append(files[i].name, files[i]);
    }
  

    //額外的參數 

    data.append("Key", "Value");

    var options = {};
    options.url = "FileUploadHandler.ashx";
    options.type = "POST";
    options.data = data;
    options.contentType = false;
    options.processData = false;
    options.success = function (result) { alert(result); };
    options.error = function (err) { alert(err.statusText); };
  
   $.ajax(options);
 
   evt.preventDefault();
  });
});
</script>

ashx: 

public void ProcessRequest(HttpContext context)
        {

          //額外參數

          string para1 = context.Request.Params.Get("key") == null  ? "" : 
            context.Request.Params.Get("key");

          if (context.Request.Files.Count > 0)
            {
                HttpFileCollection files = context.Request.Files;
                for (int i = 0; i < files.Count;i++ )
                {
                    HttpPostedFile file = files[i];
                    string fname = context.Server.MapPath("~/uploads/" + file.FileName);
                    file.SaveAs(fname);
                }
            }
            context.Response.ContentType = "text/plain";
            context.Response.Write("File(s) Uploaded Successfully!");
        }