C#: Windows Forms: What could cause Invalidate() to not redraw?

Question

I\'m using Windows Forms. For a long time, pictureBox.Invalidate(); worked to make the screen be redrawn. However, it now doesn\'t work and I\'m not sure why.

Answer 1

Invalidate() only "invalidates" the control or form (marks it for repainting), but does not force a redraw. It will be redrawn as soon as the application gets around to repainting again when there are no more messages to process in the message queue. If you want to force a repaint, you can use Refresh().