UIScrollView won't pinch to zoom. (Swift)

Question

I'm having trouble getting my UIScrollView to zoom. My code is below:

class ViewController: UIViewController, UIScrollViewDelegate {

    let imageView = UIImageView()

    @IBOutlet weak var scrollView: UIScrollView!
    override func viewDidLoad() {
        super.viewDidLoad()

        let image = UIImage(named: "cats.jpg")
        imageView.image = image
        imageView.frame = CGRect(origin: CGPointZero, size: image!.size)
        scrollView.addSubview(imageView)
        scrollView.contentSize = image!.size
        scrollView.clipsToBounds = false
        scrollView.layer.borderColor = UIColor.yellowColor().CGColor
        scrollView.layer.borderWidth = 4.0

        let scrollViewFrame = scrollView.frame
        let scaleWidth = scrollViewFrame.size.width / scrollView.contentSize.width
        let scaleHeight = scrollViewFrame.size.height / scrollView.contentSize.height
        let minScale = min(scaleWidth, scaleHeight);
        scrollView.minimumZoomScale = minScale;

        scrollView.maximumZoomScale = 1.0
        scrollView.zoomScale = minScale;
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


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

}

What am I doing wrong here? I have tried adjusting the min and max scale but doesn't make any difference. Any pointers on this would be really appreciated. Thanks!

Answer 1

Add this to viewDidLoad:

scrollView.delegate = self

The scroll view needs a delegate (your view controller) to get the view for zooming (the delegate method you implemented).