How to stop BackgroundWorker on Form's Closing event?

Question

I have a form that spawns a BackgroundWorker, that should update form\'s own textbox (on main thread), hence Invoke((Action) (...)); call.
If in Handl

Answer 1

Your backgroundworker should not use Invoke to update the textbox. It should ask the UI thread nicely to update the textbox using event ProgressChanged with the value to put in the textbox attached.

During event Closed (or maybe event Closing), the UI thread remembers that the form is closed before it cancels the backgroundworker.

Upon receiving the progressChanged the UI thread checks if the form is closed and only if not, it updates the textbox.