Finding the color of any pixel on screen

I need to find the color of any/all pixel/s on the screen. The code I got so far seems to do that but it doesn't get the pixel of my game window (another program, direct draw window app).

Here is the code...

Code:

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POINT pt;
GetCursorPos(&pt);               
               
HDC hdc = GetDC(0);
       
COLORREF pixel = GetPixel(hdc, pt.x, pt.y);

ReleaseDC(0, hdc);

cout << " red: " << (int)GetRValue(pixel)
      << " green: " << (int)GetGValue(pixel)
      << " blue : " << (int)GetBValue(pixel) << '\n';

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The idea of the program is to place the cursor over some color and the program will show you the values for that color.

HWND 0 is the desktop window, every program has its own seperate window(s) handle(s). You will have to use the HWND of your programs window.

Quote:

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Originally Posted by abachler

HWND 0 is the desktop window, every program has its own seperate window(s) handle(s). You will have to use the HWND of your programs window.

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I want to get the pixels from the entire screen not just a window.

edit:

I've discoverd that if i check the same spot hundreds of times sometimes it will show the color, so i guess it must have something to do with the game erasing with frame with black.

Yes, thats an outdated method but still in common use. Personally I 'erase' the window with the new picture. Improves performance.