Question

我是使用MFC和位图的新手。我有一个HWND，我想使用WM_PRINTCLIENT将其打印到位图上。这就是我到目前为止所做的：

编辑：

CRect rcWindow;
GetClientRect(hWnd, &rcWindow);         

HDC hDC = GetDC(hWnd);          
HDC hBitmapDC = CreateCompatibleDC(hDC);
HBITMAP hBitmap = CreateCompatibleBitmap(hDC, rcWindow.Width(), rcWindow.Height());             

SelectObject(hBitmapDC, hBitmap);

SendMessage(hWnd, WM_PRINTCLIENT, (WPARAM)hBitmapDC, PRF_CHILDREN | PRF_CLIENT | PRF_NONCLIENT);                                

CImage image;
image.Attach(hBitmap);
image.Save(_T("C:\\Test.bmp"), Gdiplus::ImageFormatBMP);

然而，这导致位图全黑。谁能看到我做错了什么？

Answer 1

尝试以下方法：

    HDC hBitmapDC = ::CreateCompatibleDC(hDC);
    HBITMAP hBitmap = ::CreateCompatibleBitmap(hDC, rcWindow.Width(), rcWindow.Height());
    ::SelectObject(hBitmapDC, hBitmap);

    // Blt the existing background into the bitmap DC
    ::BitBlt(hBitmapDC, 
             0, 0, rcWindow.Width(), rcWindow.Height(), 
             hDC, rcWindow.left, rcWindow.top, SRCCOPY);

当你完成它们时，不要忘记使用:: DeleteObject删除位图对象，使用DeleteDC删除位图DC ...

希望这有帮助

WM_PRINTCLIENT到BMP全黑了

1 个答案: