Non Client area drawing/calculating problem

[LuckyLuke]

Hi,

I've registered and created my own controls succesfully. In the windowclass style I've specified CS_OWNDC for drawing purposes. The control should have a non client area and therefore in response to the WM_NCCALCSIZE message I have this code:

[tt]
if (!wParam)
{
lprc = (LPRECT) lParam;
SetRect(lprc, lprc->left + 4, lprc->top + 20, lprc->right - 4, lprc->bottom - 3);
}
return 0;
[/tt]

This works fine, the client area gets exactly the way I want it (I don't think this is the right way however; according to MSDN you should change the client area if wParam == TRUE, but that doesn't work for me. So if you know how to do it that way, please say so ).

Drawing also goes fine, until I resize the window. I have 3 windows of this class, 2 are static and don't move and the 3rd moves. The first 2 are drawn the way it should, the 3rd also, but the drawings get erased through the WM_ERASEBKGND message. If I check the client area during the WM_ERASEBKGND message, I notice that it is the same as the window area. However if I check the client area of the non resizing controls, I see that the client area and the window area are as they should be.

Any input on this problem is welcome

 

[LuckyLuke]

I've found out that the problem lies somewhere else. I create the 3 windows with a height of 150. If this height changes, thus when moving the window, there are somehow no WM_NCCALCSIZE messages sent to that window with the wParam parameter set to FALSE. Anyone got any idea what the problem of this could be?