Change Changes in ASP.NET 4 UpdatePanel

Question

I am porting an ASP.NET application from 3.5SP1 to 4.0. The application works fine in 3.5SP1. In 4.0, I see a difference in the behavior of UpdatePanel.

We have a simple user control with a test field, a button, and some text. The user control is inside an UpdatePanel with UpdateMode = "Conditional" and ChildAsTriggers = "true".

Users enter a text box and click a button. We are conducting a search. If we find something, the content elsewhere on the page is updated - this works fine. If we do not find it, we will change the text in the user control. This change never appears.

So, I know that button and logic work. The user control does not own the UpdatePanel in which it lives, and it would be nice if it weren’t. But even if the button raises the event to the server, the contents of the update panel are not updated.

Has anyone seen this?

Answer 1

My problem turned out to be 4.0 a new client id mechanism. Check out the new features here .

4.0 is Inherit by default, and autoID is the "old" behavior. By adding this to the web.config page element:

clientIDMode="AutoID"

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