How do I know if a control of a page made a Callback?

Question

I have an ASPX page and on this page I have a control that contains an AJAX UpdatePanel. When the control makes a callback my ASPX page's *Page_Load* event is triggered, but the Page.IsCallBack property is false.

How do I know in the pages *Page_Load* event if there was a callback?

Answer 1

I have used the following code to check if a Page_Load is being triggered by an AJAX request:

if (!string.IsNullOrEmpty(Request.Headers["X-MicrosoftAjax"])) { }