Qt编程之对QGraphicsItem点击右键弹出菜单

就是对这个contextMenuEvent 事件重新实现，在这个事件函数中创建菜单，大概就是这样。

 void MyItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event)
 {
     QMenu *menu = new QMenu;
     menu->addAction("Action 1");
     menu->addAction("Action 2");
     menu->popup(event->screenPos());

     connect(menu, SIGNAL(triggered(QAction *)),
                  object, SLOT(triggered(QAction *)));
 }

referrences：

http://www.qtcentre.org/threads/5187-Popup-menu-for-a-QGraphicsItem

http://stackoverflow.com/questions/19868383/how-to-handle-right-mouse-click-event-for-qgraphicsitem