How do I make an eventhandler run asynchronously?

Question

I am writing a Visual C# program that executes a continuous loop of operations on a secondary thread. Occasionally when that thread finishes a task I want it to trigger an e

Answer 1

I prefer to define a method that I pass to the child thread as a delegate which updates the UI. First define a delegate:

public delegate void ChildCallBackDelegate();

In the child thread define a delegate member:

public ChildCallbackDelegate ChildCallback {get; set;}

In the calling class define the method that updates the UI. You'll need to wrap it in the target control's dispatcher since its being called from a separate thread. Note the BeginInvoke. In this context EndInvoke isn't required:

private void ChildThreadUpdater()
{
  yourControl.Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Background
    , new System.Threading.ThreadStart(delegate
      {
        // update your control here
      }
    ));
}

Before you launch your child thread, set its ChildCallBack property:

theChild.ChildCallBack = new ChildCallbackDelegate(ChildThreadUpdater);

Then when the child thread wants to update the parent:

ChildCallBack();