Question

在“图形视图”中设置场景，在“图形场景”（QGraphicscene的子类）中添加了“删除项目”插槽。在场景类中，通过删除键可以删除项目，但是当我从主窗口调用时，它不会删除项目。我在Delete item插槽中接到电话，但是selectedItems =0。什么可能引起问题？
在“图形”场景课程中

    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MainWindow类中

    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);
    }

当我从删除键执行正常时，它不能与工具箱删除操作一起使用。有什么问题吗？

Answer 1

在Main Window类中具有GraphicsView和GraphicScene类（子类）的私有成员以便轻松调用广告位。

  class MainWindow : public QMainWindow
  {
    Q_OBJECT

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

    private:
        GraphFrame              *mpGraphFrame;
        GraphicScene            *mpScene;
   }

MainWindow.cpp
Connect应该位于创建GraphicScene对象的位置

 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);
 }

如何从主窗口工具箱中的“图形”场景中删除项目？

1 个答案: