How to refresh screen so that closed forms actually disappear

I have multiple forms that popup during an intensive operation. For example, when a form popups asking user for something, and the user clicks OK, the form's graphics stay on the main screen, even though it is closed. How can I make it so that these gra开发者_StackOverflowphics disappear completely?

I would recommend performing the heavy work in the background (using a BackgroundWorker for instance), so that the GUI thread is not blocked. That way, the forms will be able to peform screen updates while the work is going on.

It sounds like perhaps you are doing intensive processing on your main thread, which is the thread that processes events like painting windows. Instead you should spawn a separate thread for doing your computations/tasks so that your main thread can continue.

Alternatively you can call DoEvents() periodically while doing your processing to allow the form to refresh, but using DoEvents is kind of a cludge in my opinion.

You can call the Refresh() method on the main screen form, which will force a graphics repaint.