如何在QT，label上加载的图片上画图。在网上查了查，需要子类化qlable，还有重载什么的，没看懂，

#ifndef CAMERAGROUPBOX_H#define CAMERAGROUPBOX_H#include class QPaintEvent;class CameraWidget : public QLabel{ Q_OBJECTpublic: CameraWidget(QWidget *parent=NULL); ~CameraWidget();protected: void paintEvent(QPaintEvent *event);private: QImage m_image;/