about showwindow

I tested ShowWindow in several ways - a main program window, child windows, dialog boxes. I set breakpoints to follow the step-by-step results of ShowWindow (WM_ERASEBKGND, WM_PAINT, WM_SHOWWINDOW...).

Vista is working O.K. in my tests.

I don't know what language you are using to program. My tests were with plain "C" code.

Maybe something to help: (?)
1) If you register your own class for this window, Check the "hbrBackground" setting that you register. If you want a normal background color, it should be "COLOR_WINDOW + 1".
2) If you handle the WM_ERASEBKGND message for the window, be sure your brush is initialized properly and you are returning a non-zero value.

If this doesn't help, please tell us more about what language you are programming with, and what type of window is displaying the flash of black.

LenGray-Eclipsit at 2007-9-8 >

When hbrBackground is set to NULL, you are supposed to process the erasing of the background. MSDN documentation indicates:

"If hbrBackground is NULL, the application should process the WM_ERASEBKGND message and erase the background. "

If your picture covers the entire window client area, you could process the WM_ERASEBKGND message and show your picture? The wParam field provides the DC to paint to. Show the picture and then return a non-zero value to indicate you handled the background painting.

Does this help?

LenGray-Eclipsit at 2007-9-8 >