Question

Let’s say i have three control A, B, C. They are all inherited from CDialog,
A is a main dialog , A contains B, and B contains C.
and each time i use mouse mouse drag C, B and C will move together.

This is a image:http://img507.imageshack.us/img507/7039/31709956.jpg

We know this will cause B and C to redraw themselves. and it might cause flicker.

And my question is whether not there is a method to double buffer these two dialogs B and C?

I know that in XP and vista, there is a attribute WS_EX_COMPOSITED that will help, but i don’t want to use this.

someone might suggest me to use memDC, but my problem is how can i merge the actions in B’s ondraw and C’s ondraw function into a buffer ?

Hope someone know what i said.

Thanks in advance!

Answer 1

what helpes flickering a lot is to overload the erasebackground method. This method fills the entire background with a solid color. The paint than paints all items on it. By removing the erasebackground, the paint will just paint over stuff which is already there, thus removing flickering.