在滚动视图中无法缩小图片

如何解决在滚动视图中无法缩小图片

我正在尝试进行图像预览，但是在ViewOnlyImageVC中查看图像时无法缩小图像

使用翠鸟从在线存储中检索图像，然后将其作为参数传递给ViewOnlyImageVC中的fullScreenImageView。

上一个视图控制器中的检索器功能

let selectimageVC = ViewOnlyImageVC()
       let imageView = UIImageView().kf.setimage(with: URL(string: passedCallDetails.Call_Captured_Images[index]),placeholder: nil,options: nil,progressBlock: nil) { (image) in
            switch image{
            case .success(let result):
                selectimageVC.fullScreenImageView.image = result.image
                self.navigationController?.pushViewController(selectimageVC,animated: true)
            case .failure(let error):
                self.presentAlert(withTitle: "App name",message: error.localizedDescription)
            }
        }

图像预览VC代码

class ViewOnlyImageVC : UIViewController,uiscrollviewdelegate {
    
    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }
    
    override var prefeRSStatusBarHidden: Bool {
        return true
    }
    
    var navigationBar = NavigationBarView()
    
    lazy var backBtn        : ArrowBackButton   = ArrowBackButton()

    var imageScrollView : UIScrollView = {
        let scrollImg = UIScrollView(frame:.zero)
        scrollImg.translatesAutoresizingMaskIntoConstraints = false
        return scrollImg
    }()
    
    var fullScreenImageView : UIImageView = {
        let image = UIImageView(frame:.zero)
        image.translatesAutoresizingMaskIntoConstraints = false
        image.isUserInteractionEnabled = true
        return image
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
    }
    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        updateMinZoomScaleForSize(view.bounds.size)
    }
}


//MARK: Button actions
extension ViewOnlyImageVC{
    
    @objc func dismisspopup(sender: UIButton){
        self.navigationController?.popViewController(animated: true)
    }
}

//MARK: setup UI
extension ViewOnlyImageVC{
    
    func setupUI(){
        
        imageScrollView.delegate = self
        fullScreenImageView.contentMode = .center
        view.addSubview(navigationBar)
        navigationBar.addSubview(backBtn)
        view.backgroundColor = .white
        backBtn.addTarget(self,action: #selector(dismisspopup(sender:)),for: .touchUpInside)
        view.addSubview(imageScrollView)
        imageScrollView.addSubview(fullScreenImageView)
        
        NSLayoutConstraint.activate([
            navigationBar.leftAnchor.constraint(equalTo: self.view.leftAnchor),navigationBar.rightAnchor.constraint(equalTo: self.view.rightAnchor),navigationBar.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.topAnchor),navigationBar.heightAnchor.constraint(equalToConstant: UIScreen.main.bounds.height * 0.1)
        ])
        NSLayoutConstraint.activate([
            backBtn.centerYAnchor.constraint(equalTo: navigationBar.centerYAnchor),backBtn.leftAnchor.constraint(equalTo: navigationBar.leftAnchor,constant: 20)
        ])
        NSLayoutConstraint.activate([
            imageScrollView.topAnchor.constraint(equalTo: navigationBar.bottomAnchor),imageScrollView.bottomAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.bottomAnchor),imageScrollView.leftAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.leftAnchor),imageScrollView.rightAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.rightAnchor)
        ])
        NSLayoutConstraint.activate([
            fullScreenImageView.topAnchor.constraint(equalTo: imageScrollView.topAnchor),fullScreenImageView.bottomAnchor.constraint(equalTo: imageScrollView.bottomAnchor),fullScreenImageView.leftAnchor.constraint(equalTo: imageScrollView.leftAnchor),fullScreenImageView.rightAnchor.constraint(equalTo: imageScrollView.rightAnchor),])
    }
    
    func updateMinZoomScaleForSize(_ size: CGSize){
        
        let scaleWidth = size.width / (fullScreenImageView.image?.size.width ?? 0)
        let scaleHeight = size.height / (fullScreenImageView.image?.size.height ?? 0)
        let minScale = min(scaleHeight,scaleWidth)
        imageScrollView.minimumZoomScale = minScale
        imageScrollView.zoomScale = minScale
    }
    
    func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
        return fullScreenImageView
    }
}