如何从主 Window 工具箱的图形场景中删除项目？

Question

在Graphic View中设置场景，在Graphic scene(subclass od QGraphicscene) class added Delete item slot.In scene class by delete key 我可以删除项目但是当我从 main window 调用时它不会删除项目。我在删除项目槽中接到电话，但 selectedItems = 0。可能导致问题的原因是什么？
在图形场景中class

    void GraphicScene::DeleteItems()//Delete Item slot in scene class
    {
       qDebug()<<"delete items"<< selectedItems().count();
       foreach(QGraphicsItem* item, selectedItems())
       {
            removeItem(item);
            delete item;
       }
    }

    void GraphicScene::keyReleaseEvent(QKeyEvent * keyEvent)// Delete key works fine
    {

         if (selectedItems().isEmpty())
              return;
         if(keyEvent->key() == Qt::Key_Delete)
         {
            DeleteItems();
         }
   }

在主窗口中class

    MainWindow::MainWindow(QWidget *parent) 
    {
      addToolBar(Qt::TopToolBarArea, mpEditToolbar = new 
                     QToolBar());
      DeleteAction = new QAction(QIcon(":/images/delete.png"),tr("Object 
                                       &Delete"), this);
      DeleteAction->setStatusTip(tr("Delete item"));
      connect(DeleteAction,SIGNAL(triggered()),mpGraphView  , 
              SIGNAL(DeleteObject())); // grpah view connecting to delete slot
      mpEditToolbar->addAction(DeleteAction);
    }

当我使用 delete 键工作正常时，它不适用于工具箱删除操作。有什么问题？

Answer 1

在 Main Window class 中有 GraphicsView 和 GraphicScene 的私有成员 class(subclass) 这样就可以很容易地调用插槽。

  class MainWindow : public QMainWindow
  {
    Q_OBJECT

    public:
        explicit MainWindow(QWidget *parent = 0);
        ~MainWindow();

    private:
        GraphFrame              *mpGraphFrame;
        GraphicScene            *mpScene;
   }

MainWindow.cpp
连接应该在您创建 GraphicScene 对象的地方

 MainWindow::MainWindow(QWidget *parent) 
 {
  addToolBar(Qt::TopToolBarArea, mpEditToolbar = new 
                 QToolBar());
  DeleteAction = new QAction(QIcon(":/images/delete.png"),tr("Object 
                                   &Delete"), this);
  DeleteAction->setStatusTip(tr("Delete item"));
  connect(DeleteAction,SIGNAL(triggered()),mpGraphScene  , 
          DeleteItems(); 
  mpEditToolbar->addAction(DeleteAction);
 }

如何从主 Window 工具箱的图形场景中删除项目？

How to Delete Item from Graphics scene from Main Window Tool Box?

qt

signals-slots

qgraphicsview