Author: Jonas Bilinkevicius

I'm little confused about the Invalidate / Repaint methods. I need a TForm and all 
its child components (panels, frames/ forms) to be repainted at once. If I use 
Repaint, the child windows don't seem to be repainted. Is that ok? How can I 
repaint all controls at once?

Answer:

Here is one which will force the Form to repaint (and all its children)
1   
2   RedrawWindow(Handle, nil, 0, RDW_ERASE or RDW_INVALIDATE or RDW_ALLCHILDREN);