winforms - Updating UI from a different thread

Question

I know this question has been asked before, but I feel it wasn't asked correctly.

I have an intensive operation and I'd like the UI to remain responsive. I've read a few posts that say Background worker is the best way to go, however, I think this assumes you have the source code to the intensive task.

I have a library that I have no source code for, the only way I can check on the progress is to attach to events that get fired and get information that way.

The example I saw on the MSDN site assumed one would have the source.

I know how to get progress (which is a percentage value) by attaching to events, but how do I get that value back to the UI?

Answer 1

The following answer is based on my gut feeling and have not actually done it a test with third party libs.

• Call your third party lib code as usual you call in a simple background (not BackGroundWorker) thread.
• Attach the library components' events to normal event handlers in your code (meant to update UI).

• In the event handler code should look like this:

  private void EventHandler(object sender, DirtyEventArgs e)
  {
      if (myControl.InvokeRequired)
          myControl.Invoke(new MethodInvoker(MethodToUpdateUI), e);
      else
          MethodToUpdateUI(e);
  }
  
  private void MethodToUpdateUI(object obj) 
  {
      // Update UI
  }