pinch gesture recognizer on expanded image

Question

I have added a tap gesture recognizer action to my image view. Once the image is tapped it expands to full screen and then dismisses full screen once tapped again. How would I add pinch to zoom to the image after it is already expanded. Here is my code for making the image full screen.

//expand image


let newImageView: UIImageView!

@IBAction func imageTapped(_ sender: UITapGestureRecognizer)




{
    let imageView = sender.view as! UIImageView

    let scrollView = UIScrollView(frame: self.view.frame)


    let newImageView = UIImageView(image: imageView.image)
    newImageView.frame = self.view.frame
    newImageView.backgroundColor = .black
    newImageView.contentMode = .scaleAspectFit
    newImageView.isUserInteractionEnabled = true


    let tap = UITapGestureRecognizer(target: self, action: #selector(dismissFullscreenImage))
    scrollView.addGestureRecognizer(tap)


    scrollView.delegate = self
    scrollView.minimumZoomScale = 1.0
    scrollView.maximumZoomScale = 5.0

    scrollView.addSubview(newImageView)

    self.view.addSubview(scrollView)
}

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

func dismissFullscreenImage(_ sender: UITapGestureRecognizer) {
    sender.view?.removeFromSuperview()
}

Answer 1

When you wanna show full image, let use scrollview instead imageView

let newImageView: UIImageView!

@IBAction func imageTapped(_ sender: UITapGestureRecognizer)
{
    let imageView = sender.view as! UIImageView

    let scrollView = UIScrollView(frame: self.view.frame);

    newImageView = UIImageView(image: imageView.image)
    newImageView.frame = self.view.frame
    newImageView.backgroundColor = .black
    newImageView.contentMode = .scaleAspectFit
    newImageView.isUserInteractionEnabled = true


    let tap = UITapGestureRecognizer(target: self, action: #selector(dismissFullscreenImage))
    scrollView.addGestureRecognizer(tap)

    scrollView.delegate = self
    scrollView.minimumZoomScale = 1.0
    scrollView.maximumZoomScale = 5.0

    scrollView.addSubview(newImageView)
    self.view.addSubview(scrollView)
}

and remember viewForZooming delegate func

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