c++ - 如何从 QGraphicsItem 的上下文菜单中运行函数

Question

我试图在我的 QGraphicsItem 子类中实现一个上下文菜单，如下所示：

void ImagePixmapItem::right_clicked(){
    qDebug("Got here!");
}

void ImagePixmapItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event){
    QMenu menu;
    QAction *removeAction = menu.addAction("Remove");
    QAction *markAction = menu.addAction("Mark");
    QAction *selectedAction = menu.exec(event->screenPos());

    connect(selectedAction, SIGNAL(triggered()),this, SLOT(right_clicked()));
}

我究竟做错了什么？文字“到了！” 永远不会被解雇，此外，我如何修改它以知道从菜单中选择了哪个操作？

谢谢

Answer 1

当菜单对象超出范围时，QMenu 将被删除。

试试这个：

void ImagePixmapItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event)
{
    std::auto_ptr<QMenu> menu(new QMenu(address_of_parent_widget));
    QAction *removeAction = menu->addAction("Remove");
    QAction *markAction = menu->addAction("Mark");
    QAction *selectedAction = menu->exec(event->screenPos());
    if ( selectedAction != 0 ) { 
        // see: http://doc.trolltech.com/4.3/qmenu.html#exec-2
        this->right_clicked();
    }
}