单击UIBarButton显示吐司和双击后退动作需要执行
我在导航栏中有一个UIBarButton，同时点击后退按钮（第一次点击）我需要显示吐司（如警告），双击我需要在swift中退出页面，
以下代码用于显示吐司，其工作正常，
let toastLabel = UILabel(frame: CGRect(x: 20, y: self.view.frame.size.height-100, width: 350, height: 35)) toastLabel.backgroundColor = UIColor.black.withAlphaComponent(0.6) toastLabel.textColor = UIColor.white toastLabel.textAlignment = .center; toastLabel.font = UIFont(name: "Montserrat-Light", size: 12.0) toastLabel.text = "demo" toastLabel.alpha = 1.0 toastLabel.layer.cornerRadius = 10; toastLabel.clipsToBounds = true self.view.addSubview(toastLabel) UIView.animate(withDuration: 2.0, delay: 0.1, options: .curveEaseOut, animations: { toastLabel.alpha = 0.0 }, completion: {(isCompleted) in toastLabel.removeFromSuperview() }) 请指导我完成这项任务。
override func viewDidLoad() { super.viewDidLoad() self.navigationItem.hidesBackButton = true let button = UIButton(type: .system) button.frame = CGRect(x: 0, y: 0, width: 80, height: 40) button.setTitle("Back", for: .normal) //Gesture Recognizer let singleTap = UITapGestureRecognizer(target: self, action: #selector(handleSingleTap)) singleTap.numberOfTapsRequired = 1 let doubleTap = UITapGestureRecognizer(target: self, action: #selector(handleDoubleTap)) doubleTap.numberOfTapsRequired = 2 button.addGestureRecognizer(singleTap) button.addGestureRecognizer(doubleTap) singleTap.require(toFail: doubleTap) let barButton = UIBarButtonItem(customView: button) self.navigationItem.leftBarButtonItem = barButton } @objc func handleSingleTap(sender: UITapGestureRecognizer? = nil) { let toastLabel = UILabel(frame: CGRect(x: 20, y: self.view.frame.size.height-100, width: 350, height: 35)) toastLabel.backgroundColor = UIColor.black.withAlphaComponent(0.6) toastLabel.textColor = UIColor.white toastLabel.textAlignment = .center; toastLabel.font = UIFont(name: "Montserrat-Light", size: 12.0) toastLabel.text = "demo" toastLabel.alpha = 1.0 toastLabel.layer.cornerRadius = 10; toastLabel.clipsToBounds = true self.view.addSubview(toastLabel) UIView.animate(withDuration: 2.0, delay: 0.1, options: .curveEaseOut, animations: { toastLabel.alpha = 0.0 }, completion: {(isCompleted) in toastLabel.removeFromSuperview() }) print("Single Tap detected") } @objc func handleDoubleTap(sender: UITapGestureRecognizer? = nil) { print("Double Tap detected") }
使用UIControlEventTouchDownRepeat事件，并在tapCount为2时执行操作。
在UIButton上为控件事件UIControlEventTouchDownRepeat添加目标操作，并仅在touch的tapCount为2时执行操作。如下所示在Swift 3中
button.addTarget(self, action: #selector(multipleTap(_:event:)), for: UIControlEvents.touchDownRepeat)
然后添加选择器如下
func multipleTap(_ sender: UIButton, event: UIEvent) { let touch: UITouch = event.allTouches!.first! if (touch.tapCount == 2) { // do action. } }