update problem in WS_EX_TRANPARENT
Posted on 2005-04-16
I am trying to create a tranparent window on top of other windows so I can draw and annotate on it. I used WS_EX_TRANSPARENT in creating the window. It works fine except when the window underneath changes (moved or repainted), the transparent window does not update itself. I have seen numerous people posting on the net saying that they have the same problem, but never got a satisfying answer. Is the answer that WS_EX_TRANSPARENT just does not work? If so, what's my other choice? Using layered window and set the alpha to 1% does not work since anything I draw on it will also show as transparent. I can also draw a transparent bitmap and the alpha value of the pixels individually, but I will still need a transparent background. Please help.