場景座標的原點在場景中心code
QGraphicsScene scene; scene.addLine(QLineF(0, 0, 50, 0)); scene.addLine(QLineF(0, 0, 0, 50)); scene.addLine(QLineF(0, 0, -50, 0)); scene.addLine(QLineF(0, 0, 0, -50)); scene.addEllipse(QRectF(0, 0, 50, 50)); scene.addRect(QRectF(0, 0, 25, 25)); QGraphicsView view(&scene); //必須將scene放到view中,不然不能看到圖形 view.show();