滑动手势-斯威夫特3

Question

我需要我的应用程序来响应一个滑动手势，我得到了这个代码到目前为止。但由于某种原因，当我滑动时，应用程序就崩溃了。有什么问题吗？我在xcode中使用了swift 3。谢谢

    override func viewDidLoad() {
    super.viewDidLoad()

    var swipeRight = UISwipeGestureRecognizer(target: self, action: "respondToSwipeGesture:")
    swipeRight.direction = UISwipeGestureRecognizerDirection.Right
    self.view.addGestureRecognizer(swipeRight)

    var swipeDown = UISwipeGestureRecognizer(target: self, action: "respondToSwipeGesture:")
    swipeDown.direction = UISwipeGestureRecognizerDirection.Down
    self.view.addGestureRecognizer(swipeDown)
}

func respondToSwipeGesture(gesture: UIGestureRecognizer) {

    if let swipeGesture = gesture as? UISwipeGestureRecognizer {


        switch swipeGesture.direction {
            case UISwipeGestureRecognizerDirection.Right:
                print("Swiped right")
            case UISwipeGestureRecognizerDirection.Down:
                print("Swiped down")
            case UISwipeGestureRecognizerDirection.Left:
                print("Swiped left")
            case UISwipeGestureRecognizerDirection.Up:
                print("Swiped up")
            default:
                break
        }
    }
}

Answer 1

这是由于错误：-没有用Objective选择器'respondToSwipeGesture:‘声明的方法

这意味着编译器没有找到任何方法"respondToSwipeGesture“，当您试图滑动程序时，尝试查找该方法并崩溃，因为它无法找到它。

请提供这样的行动：

let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(self.respondToSwipeGesture))

let swipeDown = UISwipeGestureRecognizer(target: self, action: #selector(self.respondToSwipeGesture))

这将解决你的问题。