return JSON from MVC equivalent to web forms - asp.net

Question

I'm trying to upload files using plupload and in MVC I have code like this:
public ActionResult Upload()
{
for (int i = 0; i < Request.Files.Count; i++)
{
var file = Request.Files[i];
file.SaveAs(AppDomain.CurrentDomain.BaseDirectory + "Uploads/" + file.FileName);
}
return Json(new { success = true }, JsonRequestBehavior.AllowGet);
}
and now I want to do same in web forms. I have added these code in my submit button click
protected void submitBtn_Click(object sender, EventArgs e)
{
for (int i = 0; i < Request.Files.Count; i++)
{
var file = Request.Files[i];
file.SaveAs(AppDomain.CurrentDomain.BaseDirectory + "Uploads/" + file.FileName);
}
}
and I need to send the success=true to my plupload javascript code to write these photos in my folder.
$(document).ready(function () {
var uploader = new plupload.Uploader({
runtimes: 'html5,flash,silverlight,html4',
browse_button: 'pickfiles',
container: document.getElementById('container'),
url: '/Admin.aspx',
flash_swf_url: '/Scripts/Moxie.swf',
silverlight_xap_url: '/Scripts/Moxie.xap',
filters: {
max_file_size: '10mb',
mime_types: [
{ title: "Image files", extensions: "jpg,gif,png" },
{ title: "Zip files", extensions: "zip" }
]
},
init: {
PostInit: function () {
document.getElementById('uploadfiles').onclick = function () {
uploader.start();
return false;
};
},
UploadProgress: function (up, file) {
_file_name = file.name;
$('#PhotoBox').val(_file_name);
console.log(file.name);
},
Error: function (up, err) {
alert("\nError #" + err.code + ": " + err.message);
}
}
});
uploader.init();
});
so Is there any equivalent of
return Json(new { success = true }, JsonRequestBehavior.AllowGet);
for asp.net Web Forms?

Answer 1

simply put
if (!IsPostBack) {
for (int i = 0; i < Request.Files.Count; i++)
{
var file = Request.Files[i];
file.SaveAs(AppDomain.CurrentDomain.BaseDirectory + "Uploads/" + file.FileName);
}
}
in your page load event and everything will okay