ios - 如何只在多次按下时才触发按钮 Action ？

Question

我是 Swift 3 的新手。目前，我有一个 UIBarButtonItem。如何让这个按钮 Action 只有在多次按下时才会触发？例如，只有当用户按下此按钮两次时，才会出现 ViewController。

Answer 1

为 UIBarButtonItem 创建自定义 View 并为自定义 View 添加 UITapGestureRecognizer 并将 numberOfTapsRequired 属性值设置为 2

示例代码:

 class viewController: UIViewController {

        var doubleTapGesture: UITapGestureRecognizer!
        var barButton: UIBarButtonItem!
        var button: UIButton!

        override func viewDidLoad() {
            super.viewDidLoad()

            button = UIButton(type: .custom)
            button.setTitle("title", for: .normal)
            button.frame = CGRect(x: 0, y: 0, width: 64, height: 30)

            doubleTapGesture = UITapGestureRecognizer(target: self, action: #selector(viewController.buttonClicked))
            doubleTapGesture.numberOfTapsRequired = 2

            button.addGestureRecognizer(doubleTapGesture)

            barButton = UIBarButtonItem(customView: button);
            navigationItem.rightBarButtonItem = barButton
        }

        func buttonClicked() {
            // Method for UITapGestureRecognizer
        }
    }