Swift 简单封装UISwipeGestureRecognizer + 闭包回调监听事件，便于不同场景的 UIView调用

typealias sendValueClosure = (swipeGesture: UISwipeGestureRecognizer) -> Void</span>class SwipeGesture:NSObject {        //声明一个闭包    var myClosure: sendValueClosure?    //下面的方法需要传入上个界面的someFunctionThatAClosure函数指针    func initWithClosure(closuer: sendValueClosure?) {        //讲函数指针赋值给myClosure闭包，该闭包中覆盖了someFunctionThatTakesAClosure函数中的局部变量等引用        self.myClosure = closuer    }            func setSwipeGesture(view:UIView){        //设置手势        let swipeRight = UISwipeGestureRecognizer(target: self, action: "respondToSwipeGesture:")        swipeRight.direction = UISwipeGestureRecognizerDirection.Right        view.addGestureRecognizer(swipeRight)                let swipeLeft = UISwipeGestureRecognizer(target: self, action: "respondToSwipeGesture:")        swipeLeft.direction = UISwipeGestureRecognizerDirection.Left        view.addGestureRecognizer(swipeLeft)                let swipeUp = UISwipeGestureRecognizer(target: self, action: "respondToSwipeGesture:")        swipeUp.direction = UISwipeGestureRecognizerDirection.Up        view.addGestureRecognizer(swipeUp)                let swipeDown = UISwipeGestureRecognizer(target: self, action: "respondToSwipeGesture:")        swipeDown.direction = UISwipeGestureRecognizerDirection.Down        view.addGestureRecognizer(swipeDown)    }        //事件    func respondToSwipeGesture(gesture: UIGestureRecognizer){                if let swipeGesture = gesture as? UISwipeGestureRecognizer {                       if let closure = self.myClosure {                closure(swipeGesture: swipeGesture)            }                    }    }}

这个类功能就是封装UISwipeGestureRecognizer，添加上下左右4种滑动手势及相应的时间，这些都不重要，重要的是：

    //声明一个闭包    var myClosure: sendValueClosure?    //下面的方法需要传入上个界面的someFunctionThatAClosure函数指针    func initWithClosure(closuer: sendValueClosure?) {        //讲函数指针赋值给myClosure闭包，该闭包中覆盖了someFunctionThatTakesAClosure函数中的局部变量等引用        self.myClosure = closuer    }

声明的闭包myClosure在类的最上面那句代码：

typealias sendValueClosure = (swipeGesture: UISwipeGestureRecognizer) -> Void

initWithClosure(closure: sendValueClosure)这个函数是被我们UIView源文件调用的。

下面respondToSwipeGesture(gesture:UIGestureRecognizer)事件触发的时候，里面的

if let closure = self.myClosure {      closure(swipeGesture: swipeGesture)}

是把UISwipeGestureRecognizer当做参数返回给闭包。

下面就是我们的 UIView 源文件调用啦：

//实例化类let mySwipeGesture = SwipeGesture()// 给 UIView 添加手势mySwipeGesture.setSwipeGesture( yourView)//调用闭包监听事件mySwipeGesture.initWithClosure { (swipeGesture) -> Void in        switch swipeGesture.direction {        case UISwipeGestureRecognizerDirection.Right:                print("Swiped right")        case UISwipeGestureRecognizerDirection.Left:                print("Swiped left")        case UISwipeGestureRecognizerDirection.Up:                print("Swiped up")        case UISwipeGestureRecognizerDirection.Down:         print("Swiped down")        default:                break        }}

是的，就是这么简单。。手势不是目的，封装不是目的，目的是学会用闭包实现数据监听及传送数据。