如何在滚动 UITableView 期间制作动画

Question

我有一个问题，是否可以在滚动 UITableView 期间在旋转 UILabel 时制作动画？那我该怎么做呢？当用户开始滚动时，UILabel 将根据滚动开始旋转！ Objective-C 和 Swift 都适合我

抱歉我的英语不好:)

based on Fogmeister solution i wrote in swift and it works Well ;)

#Swift 4

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
      let maximumHorizontalOffset: CGFloat = scrollView.contentSize.width - scrollView.frame.width
      let currentHorizontalOffset: CGFloat = scrollView.contentOffset.x
      let maximumVerticalOffset : CGFloat = scrollView.contentSize.height - scrollView.frame.height;
      let currentVerticalOffset : CGFloat = scrollView.contentOffset.y;
      let percentageVerticalOffset : CGFloat = currentVerticalOffset / maximumVerticalOffset;
      let percentageHorizontalOffset: CGFloat = currentHorizontalOffset / maximumHorizontalOffset;
      scrollMyView(scrollView, didScrollToPercentageOffset: CGPoint(x: percentageHorizontalOffset, y: percentageVerticalOffset))

    }

    func scrollMyView(_ scrollView: UIScrollView?, didScrollToPercentageOffset percentageOffset: CGPoint) {
       UIView.animate(withDuration: 0.5, animations: {
         self.myImageView.transform = CGAffineTransform(rotationAngle: (self.rotate(forOffsetPercentage: percentageOffset.y) * .pi) / 1)
       })
     }


    func rotate(forOffsetPercentage percentage: CGFloat) -> CGFloat {

      let min: CGFloat = 1.0
      let max: CGFloat = 360.0

      let value : CGFloat = (max - min) * percentage + min

    return value
}

You can watch the animation Here !

Answer 1

滚动时尝试找出滚动视图的 Y 位置。如果条件满足，那就做你的动画。

如何在滚动 UITableView 期间制作动画

How to make animation during Scrolling UITableView

scroll

core-animation

uitableview

swift

#Swift 4