[Qt-interest] Grab the desktop on Mac

[simion ploscariu]

Hi, i am trying to grab a pixmap with the desktop on Mac
 QPixmap pixmap= QPixmap::grabWindow(QApplication::desktop()->winId());;
    if(pixmap.isNull())
    {
        qDebug("QPixmap::grabWindow(QApplication::desktop()->winId());;
 -returned a null image");
    }

and the pixmap is null.
Any idea? Thx