C / C++ / MFC

hint_54 wrote:

tOC(1)

hint_54 wrote:

oc

    CImage img;
    img.Create(320,240,24);   <font color="Green">// creates a bitmap to select into the memory dc</font>
    HDC hmemdc = img.GetDC(); <font color="Green">// creates a memory DC with the bitmap selected into it</font>
    HRGN rgn = ::CreateRectRgn(20,20,100,100);
    ::InvertRgn(hmemdc, rgn);
    ::DeleteObject(rgn);
    CClientDC windowdc(this); <font color="Green">// DC for client area - same as ::GetDC()/::ReleaseDC()</font>
    ::BitBlt(windowdc, 10, 10, 320, 240, hmemdc, 0, 0, SRCCOPY);  <font color="Green">// just a test to see if rect got inverted</font>
    img.ReleaseDC();

Mark Salsbery
Microsoft MVP - Visual C++

bob16972 wrote:

I think I'm doing something unorthodox mixing GDI and GDI+

Mark Salsbery
Microsoft MVP - Visual C++

bob16972 wrote:

It uses the HDC before the graphics object goes out of scope. (Shame on them);)

Mark Salsbery
Microsoft MVP - Visual C++

Mark Salsbery wrote:

"Do not call any methods of the Graphics object between the calls to GetHDC and ReleaseHDC."

Mark Salsbery wrote:

If you let the Graphics class create its own DC, however, it "owns" the DC, and the DC it gives
you through GetHDC may be a temporary copy.

bob16972 wrote:

I'm taking it to mean that if I provide the HDC to the constructor for a graphics object, I need not bother with Graphics::GetHDC() ?

Mark Salsbery
Microsoft MVP - Visual C++

bob16972 wrote:

I'd email you an egg McMuffin if I could.

Mark Salsbery
Microsoft MVP - Visual C++