屏幕边缘手势识别UIGestureRecognizer

屏幕边缘手势的父类是平移手势，而其他六个手势的父类是UIGestureRecognizer
屏幕边缘手势的视图必需紧帖屏幕的某个边缘

以下创建手势将会添加到gestureView上

//将view的背景颜色设置为白色
 self.view.backgroundColor = UIColor.white
        //创建一个UIView
 let gestureView = UIView(frame: CGRect(x: 0, y: 100, width: 
 308, height: 308))
 gestureView.backgroundColor = UIColor.green
 self.view.addSubview(gestureView)

创建屏幕边缘手势

let screen = UIScreenEdgePanGestureRecognizer(target: self, action: #selector(screenAction))

设置支持的边缘

sscreen.edges = .left

把屏幕边缘手势添加到gestureView上

gestureView.addGestureRecognizer(screen)

实现轻扫手势关联方法screenAction

    //MARK:- 屏幕边缘手势关联方法
    func screenAction(sender:UIScreenEdgePanGestureRecognizer){
        sender.view?.backgroundColor = self.backRandomColor()
    }

定义一个backRandomColor方法用来随机变换背景颜色

 func backRandomColor()->UIColor {
        //产生0～1的随机数
        let redView = Float(arc4random_uniform(256))/255.0
        let greenView = Float(arc4random_uniform(256))/255.0
        let blueView = Float(arc4random_uniform(256))/255.0
        //产生随机颜色
        let color = UIColor(red: CGFloat(redView), green: CGFloat(greenView), blue: CGFloat(blueView), alpha: 1.0)
        return color
    }