Question

I need to get notified about asynchronous requests in ASP.NET. I used the jQuery .ajaxSend global event but it does not trigger when using UpdatePanels.

Is there a multi-browser way to detect when a request is being made on a page?

Answer 1

Jquery and the ASP.Net Ajax are two different javascript frameworks and they each handle the Ajax requests differently. As a result code in used in Jquery will not be hooked up in the ASP Ajax.

The one way I have handled this type of thing is hook into the page request manager (ScriptManager) and add methods to the InitializeRequest and EndRequest events.

Some javascript along these lines should sort out your problem.

<script type="text/javascript">

    // Get the instance of PageRequestManager.
    var PageRequestManager = Sys.WebForms.PageRequestManager.getInstance();

    // Add to the events
    PageRequestManager.add_initializeRequest(PageRequestManager_InitializeRequest);
    PageRequestManager.add_endRequest(PageRequestManager_EndRequest);

    // Called when async postback is initialized
    function PageRequestManager_InitializeRequest(sender, args)
    {
    }

    // Called when async postback calls back
    function PageRequestManager_EndRequest(sender, args)
    {
    }
</script>

EDIT:
Looking at the life cycle of the Asp.Net Ajax you could also use the beginRequest event if initializeRequest is too early.