How to process events from Buttons inside Repeaters? And what's this EnableEventValidation thing?

Question

I have a Repeater with a Button inside the ItemTemplate. I added the CommandName property to the button and registered and event handler for the ItemCommand event on the Repeater.

My problem is that when I click the button, I get an ArgumentException with a message saying something about EnableEventValidation being set to true.

(By the way, is there a way I can get the message in English, instead of a lousy Portuguese translation?)

I tried setting it to false and the ItemCommand handler is not called. If I set it to true I get the error.

The message also says something about using ClientScriptManager.RegisterForEventValidation if I trust the client (which I do). The problem is I can't make sense of the documentation for that method.

Answer 1

The only time I've ever seen this is when I was rebinding the repeater in the Page_Load on postback, rather than wrapping the binding in an if (!Page.IsPostBack). If you do this then the control that's sending the message is effectively invalid, so it fails.

Answer 2

lookout for the binding problem pointed out by Steve Robbins and you may also want to take a look at this article which I found pretty useful when I was stuck in a similar situation.