Silverlight: Threads / Delayed Actions / Asynchronous invocations/events

Question

Hi, I've got the following scenario: when a user moves the mouse out of a popup, I want an animation to happen, and five seconds later, I want to remove a PopUp.

This is the code I expected to do this with is:

private bool leftPopup = false;
public void AnimatePopupOut(object sender, MouseEventArgs e)
{
   myAnim.Begin();
   (new Thread(new ThreadStart(delayedRemovePopup))).Start();
}

private void delayedRemovePopup()
{
   leftPopup = true;
   Thread.Sleep(5000);
   PopUp.IsOpen = false;
}

The first line, "leftPopup = true" is fine, but the third, "PopUp.IsOpen = false" gives me an access violation exception, probably because this object belongs to the GUI thread. Is there any way I can gain access to the PopUp.IsOpen property? If not, is there another way that I can call an event after some time to do this?

Cheers

Nik

Answer 1

Try using the PopUp.Dispatcher.Invoke(). That will marshal your call back to the UI thread.