效果圖.png
使用CATiledLayer解決加載大圖的問題晰搀。如：地圖
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
//加載瓦片圖片
let imageName = "LiuYan_0\(Int(x))_0\(Int(y))"http://大圖切成的小圖
let tileImage = UIImage(named: imageName)
//draw tile
UIGraphicsPushContext(ctx)
tileImage?.draw(in: bounds)
UIGraphicsPopContext()
}
func viewForZooming(in scrollView: UIScrollView) -> UIView? {
return self.contentView
}
}
