Viv,

This is quite a common practice and goes way back to C++ API days and is translated into:-

Graphics.FromHwnd(this.Handle)

So if you had a design surface that you wanted to draw a XOR'ed selection marquee then you don't feel that getting the display context from the MouseMove event and drawing to it is acceptable practice?

The proofs in the pudding, so try it, create an application that requires a selection marquee through WM_PAINT and invalidate. Better yet try and recreate the marching ants selection band.

Update: I know you can create this using WM_PAINT - I am interested in speed, not if it can be done or not.

Regards
Neil