QT实现遮罩效果

void CalendarControl::DisableWidget(QWidget*_ppWidget)
{
    if(_ppWidget != NULL)
    {
        ppWidget = _ppWidget;
        oldPalette = ppWidget->palette();
        oldWindowOpacity = ppWidget->windowOpacity();
        ppWidget->setPalette(Qt::black);
        ppWidget->setWindowOpacity(0.2);//设置窗口透明度
        //ppWidget->setWindowFlags(Qt::FramelessWindowHint | ppWidget->windowFlags());//去掉标题栏
    }
}
void CalendarControl::EnableWidget()
{
    if(ppWidget != NULL)
    {
        ppWidget->setPalette(oldPalette);
        ppWidget->setWindowOpacity(oldWindowOpacity);//设置窗口透明
    }
}
void CalendarControl::closeEvent(QCloseEvent *event)
{
    EnableWidget();
}