Why dosen't BitBlt work with the DC of an invisible window as the destination?
when I show the window the client area is blank but if I use BitBlt when the window is visible it works fine. I want to make the window store a bitmap to be shown once the window is shown, it looks like I will have to create a bitmap and then BitBlt from it as soon as the window is shown but I can't see any reason why BitBlting to an invisible window can't work.
when I show the window the client area is blank but if I use BitBlt when the window is visible it works fine. I want to make the window store a bitmap to be shown once the window is shown, it looks like I will have to create a bitmap and then BitBlt from it as soon as the window is shown but I can't see any reason why BitBlting to an invisible window can't work.
The invisible window is necessarily repainted and it's background is erased when the window is displayed so anything that you painted into the DC is lost. Since the entire window is invalid anything that you paint onto the DC is erased and repainted with the background brush for that window. Select a bitmap into the DC and paint onto that then bitblt it during the WM_PAINT handler.
thanx donkey