void CAssistDlg::OnBnClickedTest() { HDC hdc = ::GetDC(NULL); HDC hdcMem = CreateCompatibleDC(hdc); HBITMAP hBmpMem = CreateCompatibleBitmap(hdc, , ); HBITMAP hBmpOld = (HBITMAP)SelectObject(hdcMem, hBmpMem); BitBlt(hdcMem, , , , , hdc, , , SRCCOPY);