I have the following ASPX structure:
<UpdatePanel id="OutsidePanel" UpdateMode="Conditional">
<div runat="server" id="myDiv">
<UpdatePanel id="InsidePanel" UpdateMode="Conditional">
<asp:ImageButton that causes a postback.. />
</UpdatePanel>
</div>
</UpdatePanel>
When the imageButton is clicked, on the server side, I change the class of myDiv. It's not getting updated. I assume this is because the div is outside of the Inside UpdatePanel. How would I force it to update?
If you are updating the class server-side, then the answer is yes. The inner update panel is being rerendered and passed back to the client, but the outer update panel is not being replaced. Anything outside the actual panel being updated won't be replaced when the AJAX callback returns. You might want to consider adding some javascript that updates the div when the result is returned as a simple solution to changing the class.
Could you not just call the Update method of the "OutsidePanel" UpdatePanel on the server when the Imagebutton in "InsidePanel" causes a postback? Or alternatively, set up ImageButton click event as a trigger for "OutsidePanel"
According to MSDN
If the UpdateMode property is set to Conditional, the UpdatePanel control's content is updated in the following circumstances:
When you call the Update method of the UpdatePanel control explicitly.
When the UpdatePanel control is nested inside another UpdatePanel control, and the parent panel is updated.
When a postback is caused by a control that is defined as a trigger by using the Triggers property of the UpdatePanel control. In this scenario, the control explicitly triggers an update of the panel content. The control can be either inside or outside the UpdatePanel control that the trigger is associated with.
When the ChildrenAsTriggers property is set to true and a child control of the UpdatePanel control causes a postback. Child controls of nested UpdatePanel controls do not cause an update to the outer UpdatePanel control unless they are explicitly defined as triggers.