Qt的右键菜单

QWidget和继承其类的Qt类通过使用void setContextMenuPolicy(Qt::ContextMenuPolicy)的枚举设置右键菜单，Qt::ContextMenuPolicy的枚举包括 NoContextMenu,DefaultContextMenu,ActionsContextMenu,CustomContextMenu,PreventContextMenu五种类型。

枚举	类型
Qt:：NoContextMenu	部件右键菜单，右键菜单的处理会传到部件的父级。
Qt:：PreventContextMenu	部件没有右键菜单，与NoContextMenu相反，处理不会延迟到部件的父级。这意味着所有鼠标右键事件都保证通过QWidget:：MousePresseEvent（）和QWidget:：mouseReleaseEvent（）传递到小部件本身。
Qt:：DefaultContextMenu	调用部件的QWidget:：contextMenuEvent（）处理程序。
Qt:：ActionsContextMenu	部件将其QWidget:：actions（）显示为上下文菜单。
Qt:：CustomContextMenu	部件发出QWidget:：customContextMenuRequested（）信号。

DefaultContextMenu的使用

设置DefaultContextMenu类型后，可重写contextMenuEvent(QContextMenuEvent *event)事件，调用菜单

void ZPushButton::contextMenuEvent(QContextMenuEvent *event)
{
    
    QMenu *mpMenu = new QMenu(this);
    QAction* m_actionOne = new QAction(this);
    QAction* m_actionTwo = new QAction(this);
    QAction* m_actionThree = new QAction(this);

    m_actionOne->setText("ActionOne");
    m_actionTwo->setText("ActionTwo");
    m_actionThree->setText("ActionThree");

    mpMenu->addAction(m_actionOne);
    mpMenu->addAction(m_actionTwo);
    mpMenu->addAction(m_actionThree);
    mpMenu->exec(QCursor::pos());//在当前鼠标位置显示
}

ActionsContextMenu的使用

使用Qt::ActionsContextMenu，在类中直接添加QAction

    setContextMenuPolicy(Qt::ActionsContextMenu);
    QAction* m_actionOne = new QAction(this);
    QAction* m_actionTwo = new QAction(this);
    QAction* m_actionThree = new QAction(this);
    
    m_actionOne->setText("ActionOne");
    m_actionTwo->setText("ActionTwo");
    m_actionThree->setText("ActionThree");
    
    addAction(m_actionOne);
    addAction(m_actionTwo);
    addAction(m_actionThree); 
    
	connect(m_actionOne, SIGNAL(triggered()), this, SLOT(actionOneSlot()));
	connect(m_actionTwo, SIGNAL(triggered()), this, SLOT(actionTwoSlot()));
	connect(m_actionThree, SIGNAL(triggered()), this, SLOT(actionThreeSlot()));

将上述代码添加到窗体部件的构造函数中，即可调用右键菜单。

CustomContextMenu的使用

	setContextMenuPolicy(Qt::ContextMenuPolicy::CustomContextMenu);
    connect(this,&ZPushButton::customContextMenuRequested,[this](const QPoint &pos){
    
        qDebug()<<"pos:"<<pos;
        QMenu *mpMenu = new QMenu(this);
        QAction* m_actionOne = new QAction(this);
        QAction* m_actionTwo = new QAction(this);
        QAction* m_actionThree = new QAction(this);

        m_actionOne->setText("ActionOne");
        m_actionTwo->setText("ActionTwo");
        m_actionThree->setText("ActionThree");

        mpMenu->addAction(m_actionOne);
        mpMenu->addAction(m_actionTwo);
        mpMenu->addAction(m_actionThree);
        mpMenu->exec(QCursor::pos());//在当前鼠标位置显示
    });