ios - 我如何检测由 CATransaction 触发的动画的完成

Question

我有一个 CALayer，我只是在 Controller 的 initWithNibName 中创建并添加到我的 View Controller 主视图的 subview 中:然后，我执行以下动画:

  [CATransaction begin];
  [CATransaction setAnimationDuration:2];
  [logoLayer setOpacity:0];
  [CATransaction commit];

我如何知道这个动画何时完成？ performSelector:延迟 2 秒。方法似乎不是“正确的方法”。

Answer 1

根据doc , [CATransaction setCompletionBlock:] 可用于您想要的。

它说

The completion block object is guaranteed to be called (on the main thread) as soon as all animations subsequently added by this transaction group have completed (or have been removed.) If no animations are added before the current transaction group is committed (or the completion block is set to a different value,) the block will be invoked immediately.

在开始动画事务之前尝试添加类似这样的内容。

[CATransaction setCompletionBlock:^{
    // Action after the animation completion
}];