Trigger an update of the UpdatePanel by a control that is in different ContentPlaceHolder

Question

I have a page with two ContentPlaceHolders. One has a DropDown and another UpdatePanel with content.

How can I trigger update to the UpdatePanel by the DropDown\'s

Answer 1

You can enforce update any of page UpdatePanels by call updatePanel1.Update() method on server side. For example during update updatePanel1 on button1.Click call updatePanel2.Update() and both panels will be updated.