自己封装一个widget的类,使用信号去连接别的,可以使用对象名去区分是哪个widget
protected:
    void paintEvent(QPaintEvent* event) override;
    void mouseDoubleClickEvent(QMouseEvent* event) override;
    void enterEvent(QEvent* event) override;
    void leaveEvent(QEvent* event) override;
signals:
    void clicked(int index);
void PictureBox::mouseDoubleClickEvent(QMouseEvent* event)
 {
     QString strObjectName = objectName();
     emit clicked(strObjectName.toInt());
 }