How to add a vertical swipe gesture to iPhone app for all screens?

Question

I\'d like to add a gesture to my app so when the user swipes vertically it triggers a method to do something. The swipe can be up or down. I\'ve never done anything with g

Answer 1

In swift 4.0, that goes on the method didFinishLaunchingWithOptions of the AppDelegate:

let swipeGesture = UISwipeGestureRecognizer(target: self, action: #selector(self.swipedScreen(swipeGesture:)))
swipeGesture.numberOfTouchesRequired = 2
swipeGesture.direction = [UISwipeGestureRecognizerDirection.up,  UISwipeGestureRecognizerDirection.down]
window?.addGestureRecognizer(swipeGesture)

And the action:

@objc func swipedScreen(swipeGesture: UISwipeGestureRecognizer){
    Swift.print("hy")
}