谁知道这句QT3的程序怎样转成QT4的程序？ [复制链接]

ImageProcess *w =
        new ImageProcess(0, "new window", Qt::WDestructiveClose | Qt::WResizeNoErase );

上面这句是QT3的，我用下句代替，编译错误
QWidget *wtemp=new QWidget;
ImageProcess *w =
        new ImageProcess(0, "new window", wtemp->setAttribute(Qt::WA_DeleteOnClose) | wtemp->setAttribute(Qt::WA_NoBackground) );

请高手指点，应该怎样改？非常感谢

Qt::WA_NoSystemBackground