Scrollview не будет увеличивать

Question

Все работает отлично, за исключением того, что я не могу увеличить изображение.

var zoomingImageView = UIImageView() 
var startingFrame : CGRect? 
var blackBackground : UIScrollView? 
var startingImageView: UIImageView? 

это где я создал Scrollview и ImageView внутри него

func performZoomingForStartImageView(imageView: UIImageView){ 


    if let keyWindow = UIApplication.shared.keyWindow { 

     blackBackground = UIScrollView(frame: CGRect(x: self.view.frame.origin.x, y: self.view.frame.origin.y, width: self.view.frame.size.width, height: self.view.frame.size.height)) 
     blackBackground?.delegate = self 
     blackBackground?.maximumZoomScale = 4.0 
     blackBackground?.minimumZoomScale = 1.0 
     blackBackground?.isScrollEnabled = true 
     blackBackground?.backgroundColor = .black 
     blackBackground?.alpha = 0.0 
     blackBackground?.isUserInteractionEnabled = true 
     blackBackground?.contentSize = CGSize(width: 0, height: self.view.frame.size.height) 
     keyWindow.addSubview(blackBackground!) 

     self.startingImageView = imageView 
     self.startingImageView?.isHidden = true 
     startingFrame = imageView.superview?.convert(imageView.frame, to: nil) 

     zoomingImageView = UIImageView(frame: startingFrame!) 
     zoomingImageView.image = startingImageView?.image 
     zoomingImageView.contentMode = .scaleAspectFit 
     zoomingImageView.isUserInteractionEnabled = true 
     zoomingImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(self.handleZoomOut))) 
     zoomingImageView.addGestureRecognizer(UILongPressGestureRecognizer(target: self, action: #selector(self.saveImage))) 
     blackBackground?.addSubview(zoomingImageView) 

     UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: [.curveEaseOut,.allowUserInteraction], animations: { 
      self.blackBackground?.alpha = 1.0 
      self.inputContainerView.alpha = 0 
      //let height = startingFrame!.height/startingFrame!.height * keyWindow.frame.widthimagedShown 
      self.zoomingImageView.frame = CGRect(x: self.view.frame.origin.x, y: self.view.frame.origin.y, width: self.view.frame.size.width, height: self.view.frame.size.height) 
      self.zoomingImageView.center = keyWindow.center 

      }, completion: nil) 

    } 


} 

это должен позволить зуммирование, но печать никогда не вызывается и я создал делегат

func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? { 
    print("hi") 
    return zoomingImageView 
} 

Answer 1

Для Swift 3 была изменена сигнатура метода.

Swift 3:

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