Question

i am using Fileupload and 3 dropdown control in update panel, 3 dropdown will be post back on dropdown selected index change event (i.e like Country,states and city… get the value from db as per country,states and city)

THE PROBLEM IS

While postback the filename path is gone from the file upload control(as expected/ or Default property).

I am converting the file to byte array, to store in the database from file upload control.

How can i retain the value or Is there any way to solve this issue.

Is there any ajax control for file upload or any free controls which retain the value after postback also…?

Or it is possible to set the value to file upload control during postback ?

Thnks in Advance

Answer 1

You can try to persist file upload value in hidden field between async post-backs using asp.net ajax event handlers.

Sys.WebForms.PageRequestManager.instance.add_beginRequest(BeginRequestHandler)
Sys.WebForms.PageRequestManager.instance.add_endRequest(EndRequestHandler)

function BeginRequestHandler(sender, args) {
  var fileUpload = document.getElementById('fileUpload');
  var hiddenUpload = document.getElementById('hiddenUpload');
  hiddenUpload.value = fileUpload.value;
}

function EndRequestHandler(sender, args) {
  var fileUpload = document.getElementById('fileUpload');
  var hiddenUpload = document.getElementById('hiddenUpload');
  fileUpload.value = hiddenUpload.value;
}