QT软件开发: 窗口顶置(一直显示在最前面)

CameraWidget::CameraWidget(QWidget *parent, int index) :
    QWidget(parent),
    ui(new Ui::CameraWidget)
{
    ui->setupUi(this);
    //隐藏标题栏
    setWindowFlags(Qt::FramelessWindowHint);//无边框 
    //设置窗口顶置: 一直在最前面.
    Qt::WindowFlags m_flags = windowFlags();
    setWindowFlags(m_flags | Qt::WindowStaysOnTopHint);
    setAttribute(Qt::WA_TranslucentBackground);
     ............................
}