UISwipeGestureRecognizer not recognized when added to UIView's subviews - swift

Question

I currently have a subclass of UIView which contains numerous subviews. I wish to add a UISwipeGesture to the subviews but unfortunately the swipe gesture is not recognized. I've set userInteractionEnabled = true and direction of the swipe gesture but nothing works.
public class CardStackView: UIView{
public var dataSource = [UIImage]()
private var swipeGuesture: UISwipeGestureRecognizer!
override public func layoutSubviews() {
for img in dataSource{
let view = AppView(image: img, frame: self.frame)
self.addSubview(view)
}
animateSubview()
self.userInteractionEnabled = true
}
func animateSubview(){
for (index, sView) in self.subviews.enumerate() {
swipeGuesture = UISwipeGestureRecognizer(target: self, action: #selector(self.swipeGuestureDidSwipeRight(_:)))
swipeGuesture.direction = .Right
sView.addGestureRecognizer(swipeGuesture)
sView.userInteractionEnabled = true
let move: CGFloat = CGFloat(-20 + index * 20)
let opacity = Float(1 - 0.2 * CGFloat(index))
sView.shadowOpacity(opacity).shadowOffset(CGSizeMake(20 - CGFloat(index) * 5, 20 - CGFloat(index) * 5)).shadowRadius(5).moveX(-move).moveY(-move).gravity().shadowColor(UIColor.grayColor()).duration(1)
.completion({
}).animate()
}
}
func swipeGuestureDidSwipeRight(gesture: UISwipeGestureRecognizer) {
print("Swiped right")
let subview = self.subviews[0]
subview.moveX(-60).duration(1).animate()
}
}
Example
class ExampleController: UIViewController {
var stackView: CardStackView!
override func viewDidLoad() {
super.viewDidLoad()
stackView = CardStackView(frame: CGRect(x: 20, y: 80, width: 200, height: 200))
stackView.dataSource = [UIImage(named: "2008")!, UIImage(named: "2008")!]
self.view.addSubview(stackView)
}
}

Answer 1

self.view.bringSubviewToFront(yourSubview)
try this code for all your subviews and if it doesn't work try this in your controller class for your CardStackView.

Answer 2

Try to call setNeedsLayout for stackView:
override func viewDidLoad() {
super.viewDidLoad()
stackView = CardStackView(frame: CGRect(x: 20, y: 80, width: 200, height: 200))
stackView.dataSource = [UIImage(named: "2008")!, UIImage(named: "2008")!]
stackView.setNeedsLayout()
self.view.addSubview(stackView)
}