BOOL SaveHwndToBmpFile(HWND hWnd, LPCTSTR lpszPath)

{

	HWND hDesktop = ::GetDesktopWindow();

	ASSERT(hDesktop);

	if(NULL == hWnd)

	{

		hWnd = hDesktop;

	}

	RECT rect;

	::GetWindowRect(hWnd, &rect);



	int nWidht = rect.right - rect.left;

	int nHeight = rect.bottom - rect.top;



	HDC hSrcDC = ::GetWindowDC(hWnd);

	ASSERT(hSrcDC);

	HDC hMemDC = ::CreateCompatibleDC(hSrcDC);

	ASSERT(hMemDC);

	HBITMAP hBitmap = ::CreateCompatibleBitmap(hSrcDC, nWidht, nHeight);

	ASSERT(hBitmap);

	HBITMAP hOldBitmap = (HBITMAP)::SelectObject(hMemDC, hBitmap);

	::BitBlt(hMemDC, 0, 0, nWidht, nHeight, hSrcDC, 0, 0, SRCCOPY);



	BITMAP bitmap = {0};

	::GetObject(hBitmap, sizeof(BITMAP), &bitmap);

	BITMAPINFOHEADER bi = {0};

	BITMAPFILEHEADER bf = {0};



	CONST int nBitCount = 24;

	bi.biSize = sizeof(BITMAPINFOHEADER);

	bi.biWidth = bitmap.bmWidth;

	bi.biHeight = bitmap.bmHeight;

	bi.biPlanes = 1;

	bi.biBitCount = nBitCount;

	bi.biCompression = BI_RGB;

	DWORD dwSize = ((bitmap.bmWidth * nBitCount + 31) / 32) * 4 * bitmap.bmHeight;



	HANDLE hDib = GlobalAlloc(GHND, dwSize + sizeof(BITMAPINFOHEADER));

	LPBITMAPINFOHEADER lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);

	*lpbi = bi;



	::GetDIBits(hMemDC, hBitmap, 0, bitmap.bmHeight, (BYTE*)lpbi + sizeof(BITMAPINFOHEADER), (BITMAPINFO*)lpbi, DIB_RGB_COLORS);



	try

	{

		CFile file;

		file.Open(lpszPath, CFile::modeCreate | CFile::modeWrite);

		bf.bfType = 0x4d42;

		dwSize += sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);

		bf.bfSize = dwSize;

		bf.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);



		file.Write((BYTE*)&bf, sizeof(BITMAPFILEHEADER));

		file.Write((BYTE*)lpbi, dwSize);

		file.Close();

	}

	catch(CFileException* e)

	{

		e->ReportError();

		e->Delete();

	}



	GlobalUnlock(hDib);

	GlobalFree(hDib);



	::SelectObject(hMemDC, hOldBitmap);

	::DeleteObject(hBitmap);

	::DeleteDC(hMemDC);

	::ReleaseDC(hWnd, hSrcDC);



	return TRUE;

}





// 调用方法

	HWND hWnd = GetSafeHwnd();

	if(hWnd)

	{

		DWORD dwStart = GetTickCount();

		SaveHwndToBmpFile(hWnd, _T("E://12.bmp"));

		DWORD dwValue = GetTickCount() - dwStart;

		CString strText(_T(""));

		strText.Format(_T("%d ms"), dwValue);

		AfxMessageBox(strText);

	}