手动控制UIView动画的进度，而不是在持续时间内自动控制 [英] Control a UIView animation's progress manually instead of automatically through the time duration

问题描述

我想设置一个UIView动画，但是我花了一段时间来控制百分比进度，让它自动为我插值。那可能吗？谢谢

I want to setup a UIView animation, but instead of it taking a given amount of time, i want to control the percentage progress and let it automatically interpolate the values for me. Is that possible? Thanks

推荐答案

我想我已经知道了。在[UIView animate ...]块之后，立即在根视图上执行以下操作：

I think i've got it. Immediately after the [UIView animate...] block, do the following on the root view:

_view.layer.speed = 0.0;
_view.layer.timeOffset = [_view.layer convertTime:CACurrentMediaTime() fromLayer:nil];

要设置比例点，请执行：

And to set the point on the scale, do:

_view.layer.timeOffset = 0..1; (where 1 is the same value as the original duration)

要恢复，类似于以下内容：

And to resume, something similar to the following:

CALayer *layer = _view.layer;
CFTimeInterval pausedTime = [layer timeOffset];
layer.speed = 1.0;
layer.timeOffset = 0.0;
layer.beginTime = 0.0;
CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
layer.beginTime = timeSincePause;

这一切都来自： https://developer.apple.com/library/ios/qa/qa1673/_index.html

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