QGraphicsScene addEllipse绘图的问题
void myView::mouseDoubleClickEvent(QMouseEvent *event)
{
QPointF eventPoint = this->mapToScene(event->pos());
startPoint = eventPoint;
QPen pen1;
pen1.setColor(Qt::black);
QBrush brush(Qt::red);
// qDebug()<<eventPoint.x()<<eventPoint.y()<<startPoint.x()<<startPoint.y();
QGraphicsEllipseItem *ellipseitem = this->scene()->addEllipse(eventPoint.x(),eventPoint.y(),10,10,pen1,brush);
this->ellipselist->append(ellipseitem);
}
以上函数在一张图片上绘制椭圆,有时侯可以画上去,有时候不可一,为什么,坐标貌似没有问题,