UIDynamicAnimator 顺序动画

Question

我正在尝试制作从菜单按钮中弹出的按钮（类似于 Path 上的 + 按钮）并使用 UIDynamicAnimator 为按钮的进出设置动画。它有效并且代码非常简单。

    _animator = [[UIDynamicAnimator alloc] initWithReferenceView:sender.superview];

    UIDynamicItemBehavior *resistance = [[UIDynamicItemBehavior alloc] initWithItems:@[_cartBtn, _chatBtn, _eventBtn]];
    resistance.resistance = 5.0f;
    [_animator addBehavior:resistance];

    CGFloat radius = 75;
    CGPoint target = sender.center;
    target.x += radius * cos(GLKMathDegreesToRadians(265));
    target.y += radius * sin(GLKMathDegreesToRadians(265));
    UISnapBehavior *snapBehavior = [[UISnapBehavior alloc] initWithItem:_cartBtn snapToPoint:target];
    [_animator addBehavior:snapBehavior];

    target = sender.center;
    target.x += radius * cos(GLKMathDegreesToRadians(225));
    target.y += radius * sin(GLKMathDegreesToRadians(225));
    UISnapBehavior *snapBehavior2 = [[UISnapBehavior alloc] initWithItem:_chatBtn snapToPoint:target];
    [_animator addBehavior:snapBehavior2];

    target = sender.center;
    target.x += radius * cos(GLKMathDegreesToRadians(185));
    target.y += radius * sin(GLKMathDegreesToRadians(185));
    UISnapBehavior *snapBehavior3 = [[UISnapBehavior alloc] initWithItem:_eventBtn snapToPoint:target];
    [_animator addBehavior:snapBehavior3];

这样，所有三个按钮一起弹出。我想问的是，是否可以使用 UIDynamicAnimator 或其他简单的方法让按钮 一个接一个 动画化？

Answer 1

显然我只需要在 addBehavior:

之间添加一个像 [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.1]]; 这样的微小延迟

UIDynamicAnimator 顺序动画

UIDynamicAnimator sequential animation

ios

uidynamicanimator