scrollView中imageView的多个动画

我有我有一个ImageView的UIScrollView。我试图实现的是：
- 当用户再次点击时放大图像以适合屏幕的全高，
- 自动启动第一个滚动到右侧的动画图像，
- 之后，开始滚动到图像中间的第二个动画，
- 最后再次开始动画滚动到图像的右侧。
我想获得漂浮在屏幕上的图像的印象。用户不能自己滚动图像。scrollView中imageView的多个动画

我已经完成了缩放的部分，但我有的问题是动画。我尝试过这样的事情，其中offset，middleOffset和endOffset是CGPoints：

override func viewDidLoad() { 
     super.viewDidLoad() 
     scrollView.delegate = self 
     setupGestureRecognizer() 
    } 

override func viewDidAppear(_ animated: Bool) { 
     super.viewDidAppear(true) 
     scrollView.panGestureRecognizer.isEnabled = false 
     scrollView.pinchGestureRecognizer?.isEnabled = false 
    } 

fileprivate func updateMinZoomScaleForSize(size: CGSize) { 
     let widthScale = size.width/imageView.bounds.width 
     let heightScale = size.height/imageView.bounds.height 
     let minScale = min(widthScale, heightScale) 

     let maxHeightScale = view.frame.height/imageView.bounds.height 
     scrollView.maximumZoomScale = maxHeightScale 

     scrollView.minimumZoomScale = minScale 
     scrollView.zoomScale = minScale 
    } 

fileprivate func updateConstraintsForSize(size: CGSize) { 
     let yOffset = max(0, (size.height - imageView.frame.height)/2) 
     imageViewTopConstraint.constant = yOffset 
     imageViewBottomConstraint.constant = yOffset 

     let xOffset = max(0, (size.width - imageView.frame.width)/2) 
     imageViewLeadingConstraint.constant = xOffset 
     imageViewTrailingConstraint.constant = xOffset 

     view.layoutIfNeeded() 
    } 

    override func viewDidLayoutSubviews() { 
     super.viewDidLayoutSubviews() 
     updateMinZoomScaleForSize(size: view.bounds.size) 
    } 

    func setupGestureRecognizer() { 
     let singleTap = UITapGestureRecognizer(target: self, action: #selector(self.handleSingleTap(recognizer:))) 
     singleTap.numberOfTapsRequired = 1 
     scrollView.addGestureRecognizer(singleTap) 
    } 

    func handleSingleTap(recognizer: UITapGestureRecognizer) { 
     if (scrollView.zoomScale > scrollView.minimumZoomScale) { 
      scrollView.setZoomScale(scrollView.minimumZoomScale, animated: true) 
     } else { 
      scrollView.setZoomScale(scrollView.maximumZoomScale, animated: true) 
     } 
    } 

func scrollViewDidScroll(_ scrollView: UIScrollView) { 

     UIView.animate(withDuration: 1, delay: 0.3, options: [], animations: { 
      scrollView.setContentOffset(offset, animated: false) 
     }, completion: { _ in 
      UIView.animate(withDuration: 1, delay: 0.3, options: [], animations: { 
       scrollView.setContentOffset(middleOffset, animated: false) 
      }, completion: { _ in 
       UIView.animate(withDuration: 1, delay: 0.3, options: [], animations: { 
        scrollView.setContentOffset(endOffset, animated: false) 
       }, completion: nil) 
      }) 
     }) 
    } 

func viewForZooming(in scrollView: UIScrollView) -> UIView? { 
    return imageView 
} 

func scrollViewDidZoom(_ scrollView: UIScrollView) { 
    updateConstraintsForSize(size: view.bounds.size) 
}

它不工作。在图像放大后加载第一个动画，但随后停止（不会崩溃）。看起来动画未完成，因为我再次点击时无法缩小图像。

来源

2016-11-09 Bastek

好吧，我发现动画块不能在scrollViewDidScroll委托方法里面。我把它们放入handleSingleTap函数中，然后它就像它应该那样工作。

来源

2016-11-09 15:34:49 Bastek

scrollView中imageView的多个动画

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