Question

From time to time my applications GUI stops redrawing. There a lot of threads that are firing all kinds of events (like timers or network data ready etc.). Also there are a lot of controls that are subscribing these events. Because of that, all the event handlers play the InvokeRequired/Invoke game. Now I figured out that when the GUI freezes a lot of threads are waiting for Invoke() to return. Looks like the message pump stopped pumping. The handlers look like this:

private void MyEventHandler( object sender, EventArgs e ) {     if ( InvokeRequired ) {         Invoke( new EventHandler( MyEventHandler ), sender, e );         return;     }      SetSomeStateVariable();     Invalidate(); } 

Any ideas?

Solution: BeginInvoke(). Looks like you should always use BeginInvoke() if you have lots of CrossThread-Events…

Thanks.

Thanks everybody.

EDIT: Looks like BeginInvoke() really solved it. No freezing until now.

Answer 1

Invoke waits until the event is handled in the GUI thread. If you want it to be asynchronous use BeginInvoke()