确定点击鼠标后点击的自定义qgraphicsitem

Question

我在识别自定义qgraphicsobject的id时遇到问题。我的自定义QgraphicsItem存储Id，启动X，Y位置和setFlag（QGraphicsItem :: ItemIsSelectable，true）;我已将我的项目推入QMap，然后在QGraphicsScene上绘制它们。在鼠标单击期间，我可以使用items（）方法获取所有项目。但是如何确定点击的项目？我可以将QGraphicsItem转换为我的类型，但我如何获得点击项目的ID？通过获取我的图形项的坐标？

我的LightObject类

public:
LightObject(qreal x, qreal y, QColor color, QGraphicsEllipseItem *parent=0);
LightObject();

void drawFocusRect(QPainter *painter);

QRectF boundingRect();

int id() const;
void setId(int id);


signals:
    void setColor(const QColor&,int);

protected:
    int type() const;
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
virtual void setGeometry(const QRectF& rect);
virtual QSizeF sizeHint(Qt::SizeHint which,
                           const QSizeF& constraint = QSizeF()) const;


public slots:


private:
    bool isSelected_;

    int id_;
    qreal xPos_;//X position on scene
    qreal yPos_;

    qreal radius = 60;

    qreal rw_;
    qreal rh_;
    QColor color_;
    QPixmap *mPixmap;

我的CustomScene类

void EffectPreviewScene::paintLights(int x,int y)
{
    int offsetX = 10;
    int offsetY = 10;
    int i = 0;
    for (int xcnt=0;xcnt<x;xcnt++){
        for (int ycnt=0;ycnt<y;ycnt++){              
            QGraphicsLayoutItem *i = new QGraphicsLayoutItem(0);

            LightObject *mLight = new LightObject(offsetX,offsetY,QColor( 255, 0, 0));//graphicsobject. store coordinates
            mLight->setId(i);//?

            mLight->setX(xcnt);
            mLight->setY(ycnt);

            qDebug() << "xcnt=" << xcnt;
            qDebug() << "ycnt=" << ycnt;
            addItem(mLight); //added

            qDebug() << "offsetX=" << offsetX;

            offsetY += 40;
            qDebug() << "offsetY=" << offsetY;

            i++;
        }
    }
}

void EffectPreviewScene::mousePressEvent(QGraphicsSceneMouseEvent *event)
{   //?
    if(!event->isAccepted()) {
        testUpdate();//repaint to green
        qDebug() << "graphics scene event not accepted";
        QGraphicsItem *item;
        item = itemAt(event->pos(),QTransform()); //Get the item at the position //?

        QList<QGraphicsItem*> potentialSelections = items();//items(event->pos());

        for(auto iter = potentialSelections.begin(); iter != potentialSelections.end() ; ++iter)
                 {
                     if((*iter)->flags() & QGraphicsItem::ItemIsSelectable)
                     {
                         item = *iter;
                     }
                 }
    qDebug () << "potentialSelections.size()="<<potentialSelections.size();
      qDebug() << "RECT=" <<item->boundingRect();//scene becomes an item

      if (item) //If there is an item at that position
      {            
          qDebug() << "found";
          qDebug() << "lights.size()"<<lights.size();
          mlight = dynamic_cast<LightObject*>(item);
         connect(mlight,&LightObject::setColor,mColorManager,ColorManager::colorChanged);
          if (mlight){
          //get x,y,id
              qDebug() << "color="<< mlight->color();
           qDebug() <<  mlight->rect();
            qDebug() << "id=" << mlight->id();
              }
          }
      }
}