VTK:基于Qt的VTK右击菜单实现

   前面试过在Qt中实现右击菜单Qt右击菜单  现在尝试在嵌套在Qt中的VTK窗口实现右击菜单 原有方式不能成功。原因也很简单：在VTK窗口发送的是VTKEvent 所以Qt中的

contextMenuEvent(QContextMenuEvent *event) 不会处理该事件。所以要另谋出路 翻阅VTK文档发现了一个实现右击菜单的实例 贴出来与大家分享：

 void GUI4::popup(vtkObject * obj, unsigned long,
             void * client_data, void *,
             vtkCommand * command)
  {
    // A note about context menus in Qt and the QVTKWidget
    // You may find it easy to just do context menus on right button up,
    // due to the event proxy mechanism in place.
  
    // That usually works, except in some cases.
    // One case is where you capture context menu events that
   // child windows don't process.  You could end up with a second
    // context menu after the first one.
  
    // See QVTKWidget::ContextMenuEvent enum which was added after the
    // writing of this example.
 
    // get interactor
    vtkRenderWindowInteractor* iren = vtkRenderWindowInteractor::SafeDownCast(obj);
    // consume event so the interactor style doesn't get it
    command->AbortFlagOn();
    // get popup menu
    QMenu* popupMenu = static_cast<QMenu*>(client_data);
   // get event location
    int* sz = iren->GetSize();
    int* position = iren->GetEventPosition();
    // remember to flip y
    QPoint pt = QPoint(position[0], sz[1]-position[1]);
    // map to global
    QPoint global_pt = popupMenu->parentWidget()->mapToGlobal(pt);
    // show popup menu at global point
    popupMenu->popup(global_pt);
  }

这是一个槽函数。使用vtkEventQtSlotConnect函数与VTK事件连接。函数介绍在之前的 VTK交互有介绍。重点是使用客户数据来传递一个菜单。

看了这个实例感觉VTK对Qt兼容性相当好 提供了这么强大的函数来实现Qt和VTK的连接。 之前看了很多人关于Qt右击菜单的实现 发现需要手动delete 否则会内存泄漏。想想看 如果不手动delete 每次右击都会new一个菜单出来。

//实现右击菜单
void fileView::contextMenuEvent(QContextMenuEvent *event)
{
   QMenu* popMenu = new QMenu(this);
QModelIndex currIndex=this->tree->indexAt(tree->viewport()->mapFromGlobal(event->globalPos()));
 int i=currIndex.row();
    // qDebug()<<"right:"<<i;
   if(i!=-1)
   {
     QAction *Rename=new QAction(QObject::tr("Rename"),popMenu);//父对象指向Menu
     popMenu->addAction(Rename);
     connect(Rename,SIGNAL(triggered(bool)),this,SLOT(slotRename()));
   }
   popMenu->exec( QCursor::pos() );
   popMenu->deleteLater();  //发出删除事件到主循环队列
}

今天看了这个实例 突然意识到 右击菜单作为一个程序的常用组件，每次用时new一个然后再delete,个人感觉过于复杂了 完全可以把其作为全局变量在构造函数中实现。这样在弹出菜单函数中直接调用该菜单实例就好 这样也不存在反复new和delete.