ios - 以模态方式显示另一个 vc 时，CABasicAnimation 已完成
<p><p>我使用下面的方式来暂停/恢复动画</p>
<pre><code>func pauseAnimation(){
var pausedTime = layer.convertTime(CACurrentMediaTime(), fromLayer: nil)
layer.speed = 0.0
layer.timeOffset = pausedTime
}
func resumeAnimation(){
var pausedTime = layer.timeOffset
layer.speed = 1.0
layer.timeOffset = 0.0
layer.beginTime = 0.0
let timeSincePause = layer.convertTime(CACurrentMediaTime(), fromLayer: nil) - pausedTime
layer.beginTime = timeSincePause
}
</code></pre>
<p>只要当前呈现 ViewController，它就可以发挥魅力。</p>
<p>当我以模态方式呈现另一个 ViewController 然后将其关闭时，无论在此呈现/关闭操作期间经过了多少时间，动画都会完成。</p>
<p>您对为什么会发生这种情况有什么建议吗？如何解决？我想补充一点，所有其他 View 都保持其状态，只有动画完成。</p>
<p>编辑:</p>
<p>我刚刚发现无论暂停/恢复都会发生这种情况 - 在这种情况下，正在进行的动画也会完成。</p>
<p>这是我展示动画实现的代码</p>
<pre><code>import Foundation
import UIKit
class CircleView: UIView {
var circleLayer: CAShapeLayer!
@IBOutlet var view: UIView!
@IBOutlet weak var progressLabel: UILabel!
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
Bundle.main.loadNibNamed("CircleView", owner: self, options: nil)
self.addSubview(view)
view.frame = self.bounds
}
override func awakeFromNib() {
super.awakeFromNib()
setupAppearance()
}
func setupAppearance() {
progressLabel.textColor = UIColor.textColor
progressLabel.font = UIFont.textTimerClock
}
func setup(progress:Double, clockwise:Bool) {
self.backgroundColor = UIColor.clear
var strokeColor = UIColor.positiveProgressColor
if !clockwise { strokeColor = UIColor.positiveProgressColor }
// Use UIBezierPath as an easy way to create the CGPath for the layer.
// The path should be the entire circle.
let circlePath = UIBezierPath(arcCenter: CGPoint(x: frame.size.width / 2.0, y: frame.size.height / 2.0), radius: (frame.size.width - 10)/2, startAngle: 0.0, endAngle: CGFloat(.pi * 2 * progress), clockwise: clockwise)
// Setup the CAShapeLayer with the path, colors, and line width
circleLayer = CAShapeLayer()
circleLayer.path = circlePath.cgPath
circleLayer.fillColor = UIColor.clear.cgColor
circleLayer.strokeColor = strokeColor.cgColor
circleLayer.lineWidth = 8.0;
// Don't draw the circle initially
circleLayer.strokeEnd = 0.0
// Add the circleLayer to the view's layer's sublayers
layer.addSublayer(circleLayer)
//add grey path
let greyCircleLayer = CAShapeLayer()
let greyCirclePath = UIBezierPath(arcCenter: CGPoint(x: frame.size.width / 2.0, y: frame.size.height / 2.0), radius: (frame.size.width - 10)/2, startAngle: 0.0, endAngle: CGFloat(.pi * 2.0), clockwise: true)
greyCircleLayer.path = greyCirclePath.cgPath
greyCircleLayer.fillColor = UIColor.clear.cgColor
greyCircleLayer.strokeColor = UIColor.appLightGrey.cgColor
greyCircleLayer.lineWidth = 1.0;
// Don't draw the circle initially
circleLayer.strokeEnd = 0.0
// Add the circleLayer to the view's layer's sublayers
layer.insertSublayer(greyCircleLayer, below: circleLayer)
if progressLabel != nil {
progressLabel.text = "10"}
}
func pauseAnimation(){
let pausedTime = circleLayer.convertTime(CACurrentMediaTime(), from: nil)
circleLayer.speed = 0.0
circleLayer.timeOffset = pausedTime
}
func resumeAnimation(){
let pausedTime = circleLayer.timeOffset
circleLayer.speed = 1.0
circleLayer.timeOffset = 0.0
circleLayer.beginTime = 0.0
let timeSincePause = layer.convertTime(CACurrentMediaTime(), from: nil) - pausedTime
circleLayer.beginTime = timeSincePause
}
func animateCircle(duration: TimeInterval, color: UIColor) {
// We want to animate the strokeEnd property of the circleLayer
circleLayer.strokeColor = color.cgColor
let animation = CABasicAnimation(keyPath: "strokeEnd")
// Set the animation duration appropriately
animation.duration = duration
// Animate from 0 (no circle) to 1 (full circle)
animation.fromValue = 0
animation.toValue = 1
// Do a linear animation (i.e. the speed of the animation stays the same)
animation.timingFunction = CAMediaTimingFunction(name: kCAAnimationLinear)
// Set the circleLayer's strokeEnd property to 1.0 now so that it's the
// right value when the animation ends.
circleLayer.strokeEnd = 1.0
// Do the actual animation
circleLayer.add(animation, forKey: "animateCircle")
}
}
</code></pre>
<p>还有一点值得一提:init()、awakeFromNib() 没有被再次调用，所以情况并非如此。</p>
<p>另一个:推送 VC 而不是模态呈现也是如此。</p></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>通常，当您显示另一个 ViewController 时，当前 ViewController 的 View 会从窗口中移除。这也会从它们的图层中删除所有待处理的动画，并且任何现有的动画完成处理程序都会使用 <code>false</code> 调用，因为动画尚未完成(另见 <a href="https://stackoverflow.com/a/21200504/2352344" rel="noreferrer noopener nofollow">https://stackoverflow.com/a/21200504/2352344</a> )。</p>
<p>返回 ViewController 后要继续动画，你应该在<code>viewWillAppear</code>中重建动画对象。</p></p>
<p style="font-size: 20px;">关于ios - 以模态方式显示另一个 vc 时，CABasicAnimation 已完成，我们在Stack Overflow上找到一个类似的问题：
<a href="https://stackoverflow.com/questions/46096086/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/46096086/
</a>
</p>
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