PatBlt does not work

Question

hey guys i need help
nothing is appearing unless I use rep "WHITENESS" or rep "BLACKNESS"

here's the code:
HBRUSH brush = CreateSolidBrush(RGB(0, 255, 255));

SelectObject(desk, brush);  
              
PatBlt(desk, 100, 100, 800, 600, PATINVERT); // the drawing goes here  
  
 DeleteObject(brush);  

yeah... it does look right but I'm not false-reporting
can somebody help? (also one more bit of information I want the code to run when a button in a Win32 GUI is clicked)

Answer 1

If I test on the Desktop DC, this works :

                HDC hDC = GetDC(NULL);  
                HBRUSH hBrush = CreateSolidBrush(RGB(0, 255, 255));  
                HBRUSH hBrushOld = (HBRUSH)SelectObject(hDC, hBrush);  
                PatBlt(hDC, 100, 100, 800, 600, PATINVERT);  
                SelectObject(hDC, hBrushOld);  
                DeleteObject(hBrush);  
                ReleaseDC(NULL, hDC);