2024年4月12日发(作者：)

9

10 QRectF MyItem::boundingRect() const

11 {

12 qreal adjust=0.5;

13 return QRectF(-18-adjust,-22-adjust,36+adjust,60+adjust);

14 }

15

16 void MyItem::paint(QPainter *painter,const QStyleOptionGraphicsItem *option,QWidget *widget)

17 {

18 painter->drawRect(0,0,200,200);

19 }

1 //

2 2

3 #include

4 #include

5 #include

6 #include

7 #include

8 #include"myitem.h"

9

10 int main(int argc, char *argv[])

11 {

12 QApplication a(argc, argv);

13 QGraphicsScene scene;

14 neRect(-300,-300,600,600);

15 mIndexMethod(QGraphicsScene::NoIndex);

16 MyItem *item=new MyItem;

17 m(item);

18 QGraphicsView view(&scene);

19 derHint(QPainter::Antialiasing);

20 heMode(QGraphicsView::CacheBackground);

21 wportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);

22 gMode(QGraphicsView::ScrollHandDrag);

23 (400,300);

24 ();

25 return ();

26 }