如何获得UIPanGesture的起点并不断计算移动距离？

Question

如何获取UIPanGesture的起点位置并不断计算移动距离？如果你能在答案中提供一些Swift代码会更好。

Answer 1

 override func viewDidLoad() {
    super.viewDidLoad()
    let pan = UIPanGestureRecognizer(target: self, action: "catchPaned")
    self.view.addGestureRecognizer(pan)
    self.view.userInteractionEnabled = true
}
func catchPaned(gesture:UIPanGestureRecognizer){
    switch(gesture.state){
    case .Began:
        let touchStart = gesture.locationInView(self.view)
    case .Changed:
        let distance = gesture.translationInView(self.view)
    default:
        println("default")
    }
}

使用locationInView获取起点，使用translationInView

获取距离

Answer 2

我自己弄清楚了。

let panGesture = UIPanGestureRecognizer(target: self, action: Selector("panFunction:"))

myView.addGestureRecognizer(panGesture)

func panFunction(sender: UIPanGestureRecognizer) {
        let translation = sender.translationInView(self.view)
        let startPoint = CGPointZero
        let distance = Double(translation.y - startPoint.y)
        println("\(distance)")
    }