Swift 3 点击屏幕任意位置隐藏键盘

func hideKeyboardWhenTappedAround() {        let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(UIViewController.dismissKeyboard))        tap.cancelsTouchesInView = false        view.addGestureRecognizer(tap)    }