问题描述
我一直在尝试滚动和缩放多个多边形路径的CALayer，特别是CAShapeLayer。我将CALayer添加到了UIScrollView中，该UIScrollView已成功启用了在CALayer上滚动。
I have been trying to scroll and zoom a CALayer, specifically a CAShapeLayer, of several polygon paths. I added the CALayer to a UIScrollView which has successfully enabled scrolling around the CALayer.
但是，缩小缩放不起作用。一些教程已经实现了使用UIScrollViewDelegate缩放UIImageView的方法，基本上是这样的：
However, pinch to zoom is not working. Several tutorials have implemented zooming a UIImageView with the UIScrollViewDelegate essentially like so:
@IBOutlet var scrollView : UIScrollView!
var imageView = UIImageView()
scrollView.addSubview(imageView)
func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
return imageView
}
但是CALayer与UIView不兼容，我有找不到关于调和差异的信息。
But CALayer is incompatible with UIView and I have found no information on reconciling the difference.
在Swift中，有没有类似的本地方法来缩放CALayer？逃避我的事情真的很简单吗？任何帮助，将不胜感激;
Is there a similar native way to zoom a CALayer in Swift? Is it something really simple that escaped me? Any help would be appreciated; apologies if I am missing the obvious.
推荐答案
经过大量挖掘后，我发现相关的 。事实证明，如果设置正确，则在CALayers上会自动处理捏缩放。我为Swift修改了演示代码，并提出了适用于我的基本结构。
After much digging I found the related documentation from Apple. Turns out pinch-to-zoom is handled automatically on CALayers if they are set up correctly. I adapted the demo code for Swift and came up with this basic structure, which worked for me.
class ViewController: UIViewController, UIScrollViewDelegate {
@IBOutlet var scrollView : UIScrollView!
var layerView = UIView()
var shapeLayer= CAShapeLayer()
func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
return layerView // Specify the layer to scroll, cannot be the UIScrollView used for scrolling
}
func scrollViewDidEndZooming(scrollView: UIScrollView, withView view: UIView!, atScale scale: CGFloat) {
// This was noted as required but no inner code is necessary
}
override func viewDidLoad() {
super.viewDidLoad()
layerView.layer.addSublayer(shapeLayer) // Attach layer to the canvas view
scrollView.addSubview(layerView) // Attach the views
// ... Add layer content, set max and min scaling values as well as layer/view sizes to encompass content
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
我希望这对其他人有帮助！
I hope this helps someone else!
这篇关于Swift：如何为CALayer启用缩放功能？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！