Detect touch location in UIImage which is in a scrollview

Question

I have the following UI hierarchy:

UIView -> UIScrollView -> UIImageView

It was necessary because i wanted to zoom my image in and out. So far so good and everything works. Now i wanted to detect the touch location of the image. I've read already a lot and it works if i just have an UIImage in an UIView. Unfortunately i need it for the first described hierarchy.

class TestController: UIViewController, UIScrollViewDelegate {

    @IBOutlet weak var scrollView: UIScrollView!
    @IBOutlet weak var myImageView: UIImageView!
    @IBOutlet var myGestureRecognizer: UITapGestureRecognizer!

    override func viewDidLoad() {
        super.viewDidLoad()

        self.myImageView.addGestureRecognizer(myGestureRecognizer)
        myImageView.userInteractionEnabled = true

    }

    override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
        let touch = touches.anyObject()! as UITouch
        let location = touch.locationInView(self.myImageView)
        println(location)
    }

    func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
        return self.myImageView
    }

    .....
}

I've tried to add "myGestureRecognizer" to UIView and also to the UIImageView and even to all 3 (UIView, UIScrollView, UIImageView) together. It just doesn't work for me and I don't know what to do.

How can I detect the location of touches (just single tap) in a UIImageView, which is placed in a UIScrollView?

Thanks in advance!

Arbitur Arbitur · Accepted Answer · 2015-03-05T14:49:02

func didTapImage(gesture: UIGestureRecognizer) {
    let point = gesture.locationInView(gesture.view)
}


override func viewDidLoad() {
    super.viewDidLoad()

    let imgView = UIImageView()
    imgView.userInteractionEnabled = true // IMPORTANT
    imgView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "didTapImage:"))
}

On UIImageView userInteractionEnabled is default to false and will not register touches.

Detect touch location in UIImage which is in a scrollview

1 Answers