Handle Exception in Update panel(asp.net Ajax and Error/Exception Handling)

Problem: While using Ajax with asp.net, if we get crash on any event which was fired by a control in a update panel we do not get any yellow screen or error page. And end user does not get any message or result.

Solution:

Step-1: Add OnAsyncPostBackError event to the script manager and set AllowCustomErrorsRedirect property to true.

<asp:scriptmanager allowcustomerrorsredirect="true" id="smBody" onasyncpostbackerror="smBody_AsyncPostBackError" runat="server"></asp:scriptmanager>

Step-2: Add the following script after the script manager(Otherwise you will get javascript error on the page).

<script type="text/javascript">

      Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);

</script>

Step-3: Add the following script to the page:

<script type="text/javascript">

    function EndRequestHandler(sender, args) {

      if (args.get_error() != undefined) {

        var Error = "Error Code: " + args.get_response().get_statusCode() + "\nError Message: " +

                    args.get_error().message;

        alert(Error);

        args.set_errorHandled(true);

        //Uncomment the following line to refresh the window after alert the error message.

        //window.location = window.location;

      }

    }

  </script>

Step-4: Write the script-manager's AsyncPostBackError event:

protected void smBody_AsyncPostBackError(object sender, AsyncPostBackErrorEventArgs e)

{

smBody.AsyncPostBackErrorMessage = e.Exception.Message;

}

Now all the postback errors will be displayed in alert message and after that the page will be reloaded :-).

Thanks. :-)