swift-懒加载

    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = UIColor.cyan
        self.navigationItem.title = "滚动视图"
        self.view.addSubview(self.scrollView)
    }

  fileprivate  lazy var scrollView:UIScrollView = {

        let Scroll:UIScrollView = UIScrollView.init(frame: UIScreen.main.bounds)
        Scroll.contentSize = CGSize.init(width:kScreenW*,height:kScreenH)
        Scroll.contentOffset = CGPoint.init(x:  , y: )
        self.automaticallyAdjustsScrollViewInsets = false
        Scroll.showsHorizontalScrollIndicator = false
        Scroll.showsVerticalScrollIndicator = false
        Scroll.isPagingEnabled = true
        Scroll.isScrollEnabled = true
        Scroll.bounces = false
        Scroll.delegate = self
        return Scroll
    }()