子視圖屏蔽父視圖手勢

父視圖要實現手勢協議UIGestureRecognizerDelegate

 let gesture = UITapGestureRecognizer(target: self, action: #selector(handleGesture))
        gesture.delegate = self
        self.view.addGestureRecognizer(gesture)

實現UIGestureRecongizerDelegata

extension ViewController: UIGestureRecognizerDelegate {
    func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldReceiveTouch touch: UITouch) -> Bool {
        if touch.view?.isDescendantOfView(self.subView) == true {
            return false
        }
        return true
    }
}