[MFC]截屏函数

亲测可用。

VOID _ScreenshotToFile(LPTSTR lpFileName)
{
	DWORD iDeskWidth = GetSystemMetrics(SM_CXSCREEN);
	DWORD iDeskHeight = GetSystemMetrics(SM_CYSCREEN);
	HDC hdcMem = CreateCompatibleDC(0);
	HDC hdcdesk = GetDC(0);
	HBITMAP bitmap = CreateCompatibleBitmap(hdcdesk, iDeskWidth, iDeskHeight);
	SelectObject(hdcMem, bitmap);
	BitBlt(hdcMem, 0, 0, iDeskWidth, iDeskHeight, hdcdesk, 0, 0, SRCCOPY);
	DeleteDC(hdcMem);
	BITMAPFILEHEADER bmfHdr; //位图属性结构 
	BITMAPINFOHEADER bi; //位图文件头结构
	memset(&bi, 0, sizeof(BITMAPINFOHEADER));
	bi.biSize = sizeof(BITMAPINFOHEADER);//固定
	bi.biWidth = iDeskWidth; //位图宽
	bi.biHeight = iDeskHeight;//位图高
	bi.biPlanes = 1; //固定
	bi.biBitCount = 24;//每个像素位数 此处24位真彩
	DWORD dwBmBitsSize = ((iDeskWidth * 24 + 31) / 32) * 4 * iDeskHeight;

	HANDLE lpbi = HeapAlloc(GetProcessHeap(),
		HEAP_ZERO_MEMORY, dwBmBitsSize + sizeof(BITMAPINFOHEADER));
	*(LPBITMAPINFOHEADER)lpbi = bi;
	GetDIBits(GetDC(0),
		bitmap,
		0,
		iDeskHeight,
		(LPSTR)lpbi + sizeof(BITMAPINFOHEADER),
		(LPBITMAPINFO)&bi,
		DIB_RGB_COLORS);

	HANDLE fh = CreateFile(lpFileName, GENERIC_WRITE,
		0, NULL, CREATE_ALWAYS,
		FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
	//位图文件头 
	bmfHdr.bfType = 0x4D42; // "BM" 
	bmfHdr.bfSize = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+dwBmBitsSize;//!!
	bmfHdr.bfReserved1 = 0;
	bmfHdr.bfReserved2 = 0;
	bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER)+(DWORD)sizeof(BITMAPINFOHEADER);
	DWORD dwWriten;
	WriteFile(fh, &bmfHdr, sizeof(BITMAPFILEHEADER), &dwWriten, NULL);
	WriteFile(fh, lpbi, sizeof(BITMAPINFOHEADER)+dwBmBitsSize, &dwWriten, NULL);
	HeapFree(GetProcessHeap(), HEAP_ZERO_MEMORY, lpbi);
	CloseHandle(fh);
}