Qt创建右键菜单的方法

编写Qt界面程序的时候，经常会用到右键菜单(ContextMenu)，目前自己知道的创建右键菜单的方法有两种，

方法1：在mousePressEvent事件中判断鼠标按下的是否是右键，进而调用创建右键菜单的函数。

void Dialog::mousePressEvent(QMouseEvent *event)//鼠标按下事件
{
    if(event->button() == Qt::RightButton)
    {
        createContextMenu();
    }
}
void Dialog::createContextMenu()//创建右键菜单函数
{
    QCursor cur=this->cursor();

    QMenu *contextMenu = new QMenu(this);
    QAction *cutAction = new QAction(tr("&New"), this);
    cutAction->setShortcut(QKeySequence::New);
    QAction *copyAction = new QAction(tr("&Copy"), this);
    copyAction->setShortcut(QKeySequence::Copy);
    QAction *pasteAction = new QAction(tr("&Paste"), this);
    pasteAction->setShortcut(QKeySequence::Paste);

    contextMenu->addAction(cutAction);
    contextMenu->addAction(copyAction);
    contextMenu->addAction(pasteAction);

    contextMenu->exec(cur.pos());
}

方法2：重新实现QWidget::contextMenuEvent()函数，

void Dialog::contextMenuEvent(QContextMenuEvent *event)//重写右键菜单
{
    QCursor cur=this->cursor();

    QMenu *contextMenu = new QMenu(this);
    QAction *cutAction = new QAction(tr("&New"), this);
    cutAction->setShortcut(QKeySequence::New);
    QAction *copyAction = new QAction(tr("&Copy"), this);
    copyAction->setShortcut(QKeySequence::Copy);
    QAction *pasteAction = new QAction(tr("&Paste"), this);
    pasteAction->setShortcut(QKeySequence::Paste);

    contextMenu->addAction(cutAction);
    contextMenu->addAction(copyAction);
    contextMenu->addAction(pasteAction);
    //setContextMenuPolicy(Qt::ActionsContextMenu);
    contextMenu->exec(cur.pos());
}