Swift 4.2，UITapGestureRecognizer在scrollview中不起作用

Question

UITapGestureRecognizer doesn't get trigged in my scrollview for some reason. I've tried many solutions with no avail.

ScrollView:

let scrollView: UIScrollView = {

    let scroll = UIScrollView()

    scroll.translatesAutoresizingMaskIntoConstraints = false
    scroll.showsHorizontalScrollIndicator = false
    scroll.showsVerticalScrollIndicator = false

    return scroll
}()

View containing all views in scrollview (so 'view' is located in this view and not directly within the scrollview):

let contentView: UIView = {

    let view = UIView()

    view.translatesAutoresizingMaskIntoConstraints = false

    return view
}()

Gesture recognizer:

let gesture = UITapGestureRecognizer(target: self, action:  #selector(self.viewTap))
            gesture.cancelsTouchesInView = false
            gesture.numberOfTapsRequired = 1
            view.addGestureRecognizer(gesture)

Action:

@objc func viewTap(sender : UITapGestureRecognizer) {
     // do stuff
}

View hierarchy ( https://imgur.com/a/wr3tge4 ):

[scrollView]
   [contentView]
      [view] <- UITapGestureRecognizer here

Thanks a ton in advance!

Answer 1

Change color of the view (with gesture) to something outstanding like red or yellow. Run your app, check first if you see your view and use "View UI Hierarchy" feature to see if your view is not actually blocked by anything