将向上滑动手势识别器添加到模式视图中

Question

我想为以模式显示的视图添加一个向上滑动识别器。然而，在模态呈现的视图中，向上滑动和向下滑动手势似乎是为视图消除保留的。当我将识别器设置为识别向左或向右滑动时，它工作得很好，但当我将其设置为识别向上滑动时，就不工作了。我该如何解决这个问题？

Answer 1

添加代理并覆盖手势：

class VC2: UIViewController {

override func viewDidLoad() {
super.viewDidLoad()
let direction: UISwipeGestureRecognizer.Direction = .up
let gesture = UISwipeGestureRecognizer(target: self, action: #selector(swipeAction(sender:)))
gesture.direction = direction
gesture.delegate = self
self.view.addGestureRecognizer(gesture)
}

@objc func swipeAction(sender: UISwipeGestureRecognizer) {
print(sender.direction)
}
}
extension VC2: UIGestureRecognizerDelegate {
func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return false
}
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}
}