CATiledLayer的使用 CATiledLayer的使用

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效果图.png 【CATiledLayer的使用】使用CATiledLayer解决加载大图的问题。如：地图

class ViewController: UIViewController, CALayerDelegate, UIScrollViewDelegate {var contentView:UIView?@IBOutlet weak var scrollView: UIScrollView!override func viewDidLoad() { super.viewDidLoad() let rect = CGRect(x: 0, y: 0, width: 1280, height: 960)let contentView = UIView(frame: rect) //瓦片 let tiledLayer = CATiledLayer() tiledLayer.frame = rect tiledLayer.delegate = self contentView.layer.addSublayer(tiledLayer) scrollView.addSubview(contentView) scrollView.contentSize = contentView.frame.size //draw layer tiledLayer.setNeedsDisplay() self.contentView = contentView }func draw(_ layer: CALayer, in ctx: CGContext) { let layer = layer as! CATiledLayer//配置瓦片位置 let bounds = ctx.boundingBoxOfClipPath let x = bounds.origin.x / layer.tileSize.width let y = bounds.origin.y / layer.tileSize.height//加载瓦片图片 let imageName = "LiuYan_0\(Int(x))_0\(Int(y))"//大图切成的小图 let tileImage = UIImage(named: imageName)//draw tile UIGraphicsPushContext(ctx) tileImage?.draw(in: bounds) UIGraphicsPopContext() }func viewForZooming(in scrollView: UIScrollView) -> UIView? { return self.contentView } }

Github地址： https://github.com/LJjack/LearnCATiledLayer