iOS系统SDK实现毛玻璃效果（swift版）系统的毛玻璃效果  iOS8.0才加上的 ，之前的只有自定义或者使用第三方了

import UIKit

class ScrollTestController: UIViewController {
    
    var  scrollView:UIScrollView!
    var  dataArray = NSMutableArray()
    
    // 懒加载
    lazy var lasyEffectView:UIVisualEffectView = {
        // iOS8 系统才有
        let tempEffectView = UIVisualEffectView(effect: UIBlurEffect(style: UIBlurEffectStyle.Light))
        tempEffectView.frame = self.view.bounds;
        tempEffectView.alpha = 0.8
        // 添加手势
        let tap = UITapGestureRecognizer(target: self, action: Selector("effectViewTouch:"))
        tempEffectView.addGestureRecognizer(tap)
        return tempEffectView
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        self.title = "UIScrollView"
        // 添加nav右侧按钮
        self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "毛玻璃", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("showEffectView"))
        
        // UIScrollView
        self.dataArray = ["1.jpg","2.jpg","3.jpg","4.jpg","IMG_0542.jpg"];
        self.scrollView = UIScrollView(frame: self.view.bounds)
        self.scrollView.pagingEnabled = true
        self.scrollView.userInteractionEnabled = true;
        self.scrollView.showsHorizontalScrollIndicator = false;
        self.scrollView.backgroundColor = UIColor.whiteColor()
        
        for var i = 0; i < 5 ;i++ {
            
            let X = self.scrollView.frame.size.width * CGFloat(i)
            
            var imgView = UIImageView(frame: CGRectMake(X, 0, self.scrollView.frame.size.width, self.scrollView.frame.size.height))
            imgView.contentMode = UIViewContentMode.ScaleToFill
            imgView.image = UIImage(named: (self.dataArray[i] as? String)!)
            
            self.scrollView.addSubview(imgView)
            
        }
        
        self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * 5.0, 0.0)
        self.view.addSubview(self.scrollView)
    }
    
    func showEffectView() {
        // 点击显示毛玻璃的判断
        
        if (lasyEffectView.superview != nil) {
            lasyEffectView.removeFromSuperview()
        }else{
            self.view.addSubview(lasyEffectView)
        }
    }
    
    func effectViewTouch(tap:UITapGestureRecognizer) {
        // 移除毛玻璃
        if (lasyEffectView.superview != nil) {
            lasyEffectView.removeFromSuperview()
        }
    }
    

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()

    }
   
}

正常：

毛玻璃效果：