WPF repaint issue

I am having an issue with repaint of my WPF control.

The WPF control is added as an ElementHost.Child for a Windows form.

When Windows 7 goes into powersave mode and is brought back to normal (by moving the mous开发者_Python百科e or key press on keyboard), the rest of Windows form controls are repainted, however the WPF part is not repainted(and the Win 7 background is visible in that area).

On Minimize and maximise of the application, the WPF part is repainted.

Anyone has any idea about this problem?

The solution for this issue was provided in MSDN magazine a while back. It shows how you can make your WPF applications "power-aware" i.e. respond to power notifications. It's an amazing article and a "must-read".

Check this link: Make Your WPF Apps Power-Aware

You can browse the source code online or download it from here: Code for PowerAware

Technologies used:

• WPF
• .Net Framework 3.0
• Windows Vista / Windows XP

Generally, in windows forms calling .Invalidate() on a Control will cause it to repaint itself (via setting the entire control's validation rect to "dirty" and then letting it invoke its own paint event asynchronously. -- If you just invoke the Paint method in winforms without Invalidating first, you will only be able to redraw the portion that was previously marked as dirty -- as windows uses the Dirty Rectangles approach to save on redraw time.)

Hopefully you can either call .Invalidate() on your WPF host control or just call .Invalidate() on the form itself (e.g. "this.Invalidate();")

Enabling double buffering on your form might also help, but I am unsure of this -- it's worth the experiment though.

@Hasan above gave you part of the answer -- how to hook into the windows message pump which and receive windows power event notifications -- but by itself will not cause your window to be repainted (at least from what I can tell) -- it's more of a notification that says "hey, you're about to have that problem you hate. Sucks to be you."

So this is probably as simple as hooking into Hasan's message pump stuff and then calling "this.Invalidate();" any time a power event notification is received. Though that solution may be a little bit overkill.

If that's not enough you may have to tell the WPF control itself to Invalidate... which it can't do, because it doesn't have that method. The documentation suggests that .InvalidateVisual() is the equivalent, but my experience has lead me to believe otherwise. Other than invalidating at the winform's level, I can't help you. If you find the answer, please post it!