Thread: GetPixel and getting a screenshot.

You do realize that you do not need either GetPixel or SetPixel calls. Both can be accomplished by the use of bit shifting to get or set the appropriate RGB values.

Code:

	HDC hdcc = CreateCompatibleDC(hdc);
//hdc - is your dc which you copy from

	HBITMAP hBm = CreateCompatibleBitmap(hdc, iSrcW, iSrcH);
//iSrcW, iSrcH - size of you sourse hdc
	HBITMAP hOldBm = (HBITMAP)SelectObject(hdcc, hBm);
	BitBlt(hdcc, 0, 0, iSrcW, iSrcH, hdc, iX, iY, SRCCOPY);

// now, get info from copied bitmap
	BITMAP bm;
	memset(&bm, 0, sizeof BITMAP);
	int iErr = GetObject(hBm, sizeof(BITMAP), &bm);
	iErr = GetLastError();
	iBPP = bm.bmBitsPixel;
	DIBSECTION dis;
	iErr = GetObject(hBm, sizeof(DIBSECTION), &dis);

	int length = (bm.bmWidth * bm.bmHeight) * (bm.bmBitsPixel>>3);
	if(0 == length)
		return NULL;// nothing to do

// Ok, bitmap info now
	BITMAPINFO bi;
	memset(&bi, 0, sizeof BITMAPINFO);
	BYTE *pBits = new BYTE[length];

	bi.bmiHeader.biSize          = sizeof(BITMAPINFOHEADER);
	bi.bmiHeader.biWidth         = bm.bmWidth;
	bi.bmiHeader.biHeight        = bm.bmHeight;
	bi.bmiHeader.biPlanes        = 1;
	bi.bmiHeader.biBitCount      = bm.bmPlanes * bm.bmBitsPixel;
	bi.bmiHeader.biCompression   = 0;
	bi.bmiHeader.biSizeImage     = 0;
	bi.bmiHeader.biXPelsPerMeter = 0;
	bi.bmiHeader.biYPelsPerMeter = 0;
	bi.bmiHeader.biClrUsed       = 0;
	bi.bmiHeader.biClrImportant  = 0;

	LPBYTE lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, length);

	int iBits = GetDIBits(hdc, hBm, 0, bm.bmHeight, lpBits, &bi, DIB_RGB_COLORS);

//.......  now you got bits of your pixels in lpBits
// remember, that y-axis begun from bottom of screen
// and don't forget:

	GlobalFree(lpBits);
	SelectObject(hdcc, hOldBm);
	DeleteObject(hBm);
	DeleteDC(hdcc);

Good luck!

Originally Posted by DeskEx

Good luck!

See MSDN code.