SwipeGestureRecognizer 滑动速度超过阈值时调用函数[关闭]

Question

我目前正在编写一个应用程序，其中包含一个 UIView 和一个 UISwipeGestureRecognizer

我希望识别器能够识别用户向识别器方向拖动的速度。当速度足够高（超过特定阈值）时，应该发生自定义操作。和this post基本一样，但是我需要用Swift写的。

我如何将它翻译成 Swift 或者有更好的方法吗？

当前代码，标记为 cmets 的 Xcode 错误。

开始接触：

override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {


        //avoid multi-touch gesture
        if(touches.count > 1){
            return;
        }

        if let touch:UITouch = touches.first as? UITouch{
            let locator:CGPoint = touch.locationInView(self.view!)
            start = locator
            startTime = touch.timestamp
        }

触摸结束：

    override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) {

    if let touch:UITouch = touches.first as? UITouch{
        let locator:CGPoint = touch.locationInView(self.view!)

        var dx:CGFloat = (locator.x - start!.x);
        var dy:CGFloat = (locator.y - start!.y);
        var magnitude:CGFloat = sqrt(dx*dx+dy*dy)

        if (magnitude >= kMinDistance) {
            // Determine time difference from start of the gesture
            var dt:CGFloat = CGFloat(touch.timestamp - startTime!)
            if (dt > kMinDuration) {
                // Determine gesture speed in points/sec
                var speed:CGFloat = magnitude / dt;
                 if (speed >= kMinSpeed && speed <= kMaxSpeed) {
                    // Swipe detected
                    swipedView()
    }}}}}

Answer 1

var start:CGPoint?
var startTime:NSTimeInterval?

var kMinDistance:CGFloat   = 25.0
var kMinDuration:CGFloat   = 0.1
var kMinSpeed:CGFloat      = 100.0
var kMaxSpeed:CGFloat      = 500.0

override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
    //avoid multi-touch gesture
    if(touches.count > 1){
        return;
    }

    if let touch:UITouch = touches.first as? UITouch{
        let location:CGPoint = touch.locationInView(self.view!)
        start = location
        startTime = touch.timestamp
    }
}

override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) {
    if let touch:UITouch = touches.first as? UITouch{
        let location:CGPoint = touch.locationInView(self.view!)

        var dx:CGFloat = location.x - start!.x;
        var dy:CGFloat = location.y - start!.y;
        var magnitude:CGFloat = sqrt(dx*dx+dy*dy)

        if (magnitude >= kMinDistance) {
            // Determine time difference from start of the gesture
            var dt:CGFloat = CGFloat(touch.timestamp - startTime!)
            if (dt > kMinDuration) {
                // Determine gesture speed in points/sec
                var speed:CGFloat = magnitude / dt;
                if (speed >= kMinSpeed && speed <= kMaxSpeed) {
                    // Swipe detected
                }
            }
        }
    }
}

老实说他还没有经过测试，但我需要一些这样的代码，所以这是在旅途中转换的。

编辑： 经过测试，似乎可以与 Swift 1.2 一起使用
请阅读您的问题下方的 cmets，并阅读 How to Ask 以了解您的下一个问题。这次你很幸运，我需要这个代码:)