美文网首页
iOS ~CollectionView 渐变色背景

iOS ~CollectionView 渐变色背景

作者: 派大星的博客 | 来源:发表于2019-02-14 13:01 被阅读8次
    IMG_1574.JPG

    代码实现

        private lazy var gradientLayer : CAGradientLayer = {
            let TColor : UIColor = UIColor(fromHexString: "FF8E8A")
            let BColor = UIColor.white
            let gradientColors: [CGColor] = [TColor.cgColor, BColor.cgColor]
            let gradientLayer: CAGradientLayer = CAGradientLayer()
            gradientLayer.colors = gradientColors
            gradientLayer.startPoint = CGPoint(x: 0, y: 0)
            gradientLayer.endPoint = CGPoint(x: 0, y: 1)
            gradientLayer.frame = CGRect(x: 0, y: 0, width: ScreenWidth, height: ScreenHeight)
            return gradientLayer
        }()
        
        override func viewDidLoad() {
            super.viewDidLoad()
    
            view.backgroundColor = UIColor.white
            view.addSubview(collectionView)
    
            // **重点解析**
            gradientLayer.zPosition = -1
            collectionView.layer.insertSublayer(gradientLayer, at: 0)
        }
    
    

    重点解析

    zPosition

    The layer’s position on the z axis. Animatable.

    var zPosition: CGFloat { get set }

    Discussion

    The default value of this property is 0. Changing the value of this property changes the front-to-back ordering of layers onscreen. Higher values place this layer visually closer to the viewer than layers with lower values. This can affect the visibility of layers whose frame rectangles overlap.

    译: 此属性的默认值为0。更改此属性的值将更改屏幕上层的前后顺序。较高的值比较低值的层在视觉上更接近查看器。这可能会影响框架矩形重叠的图层的可见性。

    相关文章

      网友评论

          本文标题:iOS ~CollectionView 渐变色背景

          本文链接:https://www.haomeiwen.com/subject/htxeeqtx.html