Forcing full redraw of form background

Question

Hi.

I've created a form which uses controls with transparent edges. The problem I'm now facing is that the cleverness of the .net Compact framework makes sure that the background (The form area beneath the control) isn't drawn since it believes that this won't be visible. This results in the rather interesting, but ugly, result that the transparent areas of the control shows whatever was visible in the background when the app was launched.

Is there any way of forcing a form to repaint itself completely? Including the areas it assumes won't be visible?

Thomas Samuelsen · Answer

Hi. Thanks for the reply. I'm overriding the OnPaint methods of the form and the transparent control and letting the framework handle the calling of these. But I actually found a solution to this. By creating a graphics object for the form using it's CreateGraphics method instead of using the one you can fetch from the paintEventArgs you avoid this optimizing clipping. And by making sure that the transparent buttons are hidden while the background is drawn then I'm sure the background is properly drawn. Then I show the buttons thereby forcing them to be repainted on top of this complete background and thus getting the desired result.

Jan Montano · Answer

How are you rendering the control? Perhaps this link could help. Creating transparent Windows Forms controls.