测试 UIView 是否处于动画中间 [英] Test whether a UIView is in the middle of animation

问题描述

有什么方法可以判断 UIView 是否在动画中间?当我在移动时打印出视图对象时，我注意到有一个动画"条目:

Is there any way to tell if a UIView is in the middle of an animation? When I print out the view object while it is moving I notice that there is an "animations" entry:

search bar should end editing: <UISearchBar: 0x2e6240; frame = (0 0; 320 88); text = ''; autoresize = W+BM; animations = { position=<CABasicAnimation: 0x6a69c40>; bounds=<CABasicAnimation: 0x6a6d4d0>; }; layer = <CALayer: 0x2e6e00>>

当动画停止并打印视图时，动画"条目现在消失了:

When the animation has stopped and I print the view, the "animations" entry is now gone:

search bar should end editing: <UISearchBar: 0x2e6240; frame = (0 0; 320 88); text = ''; autoresize = W+BM; layer = <CALayer: 0x2e6e00>>

推荐答案

A UIView 有一个层 (CALayer).您可以发送 animationKeys 到它，它将为您提供一组键，用于标识附加到图层的动画.我想如果有任何条目，则动画正在运行.如果您想更深入地挖掘，请查看 CAMediaTiming 协议.它提供有关当前动画的更多信息.

A UIView has a layer (CALayer). You can send animationKeys to it, which will give you an array of keys which identify the animations attached to the layer. I suppose that if there are any entries, the animation(s) are running. If you want to dig even deeper have a look at the CAMediaTiming protocol which CALayer adopts. It does some more information on the current animation.

重要:如果您使用nil 键([layer addAnimation:animation forKey:nil])添加动画，animationKeys 返回 nil.

Important: If you add an animation with a nil key ([layer addAnimation:animation forKey:nil]), animationKeys returns nil.

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