一時停止したアニメーションとNSInternalInconsistencyExceptionのためにアプリケーションがクラッシュする

Question

UIViewをプルアップしてスワイプして画面をアニメーション表示します。私はそれを行うためにこのコードを使用します：

private var _animator: AnyObject? 
@available(iOS 10.0, *) 
var animator: UIViewPropertyAnimator? { 
    get { 
     return _animator as? UIViewPropertyAnimator 
    } 
    set { 
     _animator = newValue 
    } 
} 
var haveTheySwiped = false 
var haveTheyNotSwiped = true 

@available(iOS 10.0, *) 
func handlePan(recognizer: UIPanGestureRecognizer) { 
    let vel = recognizer.velocity(in: self) 
     switch recognizer.state { 
     case .began: 
      if vel.y < 0 && !haveTheySwiped { 
       animator = UIViewPropertyAnimator(duration: 1, curve: .easeOut, animations: { 
        self.backgroundImage.frame = self.backgroundImage.frame.offsetBy(dx: 0, dy: -603) 
       }) 
       haveTheySwiped = true 
       isScanVisible = true 
      } else if vel.y > 0 && haveTheySwiped { 
       animator = UIViewPropertyAnimator(duration: 1, curve: .easeOut, animations: { 
        self.backgroundImage.frame = self.backgroundImage.frame.offsetBy(dx: 0, dy: 603) 
       }) 
       haveTheySwiped = false 
       isScanVisible = false 
      } 
      animator?.pauseAnimation() 
      print(backgroundImage.frame.origin) 
     case .changed: 
      let translation = recognizer.translation(in: backgroundImage) 
      if vel.y < 0 { 
       animator?.fractionComplete = translation.y/-603 
      } else if vel.y > 0 && haveTheySwiped == true { 
       animator?.fractionComplete = translation.y/603 
      } 
     case .ended: 
      animator?.continueAnimation(withTimingParameters: nil, durationFactor: 0) 
     case .possible: break 
     default: break 
     } 
} 

しかし、最近私はバグに出くわしました。私はプルアップしようとすると、UIViewのは表示されず、私は私の指を持ち上げるときに、このエラーでアプリがクラッシュ：

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'It is an error to release a paused or stopped property animator. Property animators must either finish animating or be explicitly stopped and finished before they can be released.'

は、誰もがこれに遭遇していますか？これが起こる原因を解明するのに役立つでしょう。どんな助けも非常に高く評価されます。事前にありがとう！

乾杯、 Thoe

Answer 1

の実装、その後stopAnimation（BOOL）（時：UIViewAnimatingPosition）finishAnimationは、問題をクリアする必要があります。

This class adopts the UIViewAnimating and UIViewImplicitlyAnimating protocols, which define the methods for starting, stopping, and modifying your animations. For more information about the methods of those protocols, see UIViewAnimating and UIViewImplicitlyAnimating .

https://developer.apple.com/documentation/uikit/uiviewanimating

func stopAnimation(Bool) Stops the animations at their current positions. Required.

func finishAnimation(at: UIViewAnimatingPosition) Finishes the animations and returns the animator to the inactive state. Required.