swift – 如何识别所有4个方向的滑动

您需要为每个方向有一个UISwipeGestureRecognizer。这有点怪异，因为UISwipeGestureRecognizer.direction属性是一个选项样式的位掩码，但每个识别器只能处理一个方向。你可以将它们全部发送到同一个处理程序，如果你想，并将其排序，或发送到不同的处理程序。这里有一个实现：

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
        }
    }
}

Swift 3：

override func viewDidLoad() {
    super.viewDidLoad()

    let swipeRight = UISwipeGestureRecognizer(target: self,action: #selector(self.respondToSwipeGesture))
    swipeRight.direction = UISwipeGestureRecognizerDirection.right
    self.view.addGestureRecognizer(swipeRight)

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