Q图形项目沿路径移动

Question

是否可以动画化QGraphicsItem，使其沿QGraphicsScene/QGraphicsView中的某个路径移动？

类似于这个演示，白点沿着齿轮移动——一条闭合曲线。

如果是这样的话，那怎么办呢？

Answer 1

在这里找到了一个解决方案：

QGraphicsItem *ball = new QGraphicsEllipseItem(0, 0, 20, 20);
QTimeLine *timer = new QTimeLine(5000);
timer->setFrameRange(0, 100);
QGraphicsItemAnimation *animation = new QGraphicsItemAnimation;
animation->setItem(ball);
animation->setTimeLine(timer);
animation->setPosAt(0.f / 200.f, QPointF(0, 0));
animation->setPosAt(10.f / 200.f, QPointF(0, 30));
animation->setPosAt(20.f / 200.f, QPointF(20, 30));
animation->setPosAt(30.f / 200.f, QPointF(20, 20));
animation->setPosAt(40.f / 200.f, QPointF(30, 20));
animation->setPosAt(50.f / 200.f, QPointF(30, 30));
animation->setPosAt(60.f / 200.f, QPointF(40, 30));
animation->setPosAt(70.f / 200.f, QPointF(40, 60));
animation->setPosAt(80.f / 200.f, QPointF(50, 60));
animation->setPosAt(90.f / 200.f, QPointF(50, 0));
animation->setPosAt(100.f / 200.f, QPointF(70, 0));
animation->setPosAt(110.f / 200.f, QPointF(70, 10));
animation->setPosAt(120.f / 200.f, QPointF(80, 10));
QGraphicsScene *scene = new QGraphicsScene();
scene->setSceneRect(0, 0, 250, 250);
scene->addItem(ball);
ui->graphicsView->setScene(scene);
timer->start();