How to make viewing images always the center of the screen when scaling by scrolling?

Question

Now I have the following view hierarchy:

• View
  • Scroll view
    • Scale view container
      • Turn Container
        • View map image
          • Arrow image

My view hierarchy is a little complicated, because I need both scale and rotation, and I also need to keep the map position and arrows connected, I worked for a long time and found this solution.

Now My question is, how to Arrow Image Viewalways save in the center of the screen when scaling?

Here is my code:

func viewForZooming(in scrollView: UIScrollView) -> UIView? {
    return Container For Scale View
}

func scrollViewDidZoom(_ scrollView: UIScrollView) {
    let imageViewSize = MapImageView.frame.size
    let scrollViewSize = scrollView.bounds.size

    let verticalPadding = imageViewSize.height < scrollViewSize.height ? (scrollViewSize.height - imageViewSize.height) / 2 : 0
    let horizontalPadding = imageViewSize.width < scrollViewSize.width ? (scrollViewSize.width - imageViewSize.width) / 2 : 0

    scrollView.contentInset = UIEdgeInsets(top: verticalPadding, left: horizontalPadding, bottom: verticalPadding, right: horizontalPadding)
}

Answer 1

Here you need math

, center UIView

, - viewBase

        var center = self.view.center

         let convertedImagePoint = self.viewBase.convert(imageView.center, to: self.view)

Difff

        let diff = convertedImagePoint.y - center.y


        DispatchQueue.main.async {
            self.scrollView1.contentOffset.y += diff
        }

,