why not to send WM_PAINT manually

Question

I have read that I should never send WM_PAINT manually and should call InvalidateRect instead but didn\'t found anything about why not, however. So

Answer 1

If you want to trigger an immediate repaint, the correct approach is to either:

1. Use InvalidateRect() followed by UpdateWindow().

2. Use RedrawWindow().

Those will trigger a new WM_PAINT message to be generated.