swift - 如何在swift中将从左到右的动画添加到textlayer

Question

我正在尝试快速创建一个视频编辑器。目前，我需要添加一个文本层，我需要在其中从右到左导航文本。下面给出了我使用的代码

let textLayer = CATextLayer()
textLayer.backgroundColor = UIColor.clearColor().CGColor
textLayer.foregroundColor = UIColor.whiteColor().CGColor
textLayer.string = "T E S T"
textLayer.font = UIFont(name: "Helvetica", size: 28)
textLayer.shadowOpacity = 0.5
textLayer.alignmentMode = kCAAlignmentCenter
textLayer.frame = CGRectMake(0, 50, showInBounds.width,showInBounds.height/6)
textLayer.shouldRasterize = true

let parentLayer = CALayer()
let videoLayer = CALayer()
parentLayer.frame = CGRectMake(0, 0, showInBounds.width, showInBounds.height);
videoLayer.frame = CGRectMake(0, 0, showInBounds.width,  showInBounds.height);
parentLayer.addSublayer(videoLayer)
parentLayer.addSublayer(textLayer)

mainComposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, inLayer: parentLayer)
return (mixComposition, mainComposition)

现在，出现了文本，但导航不起作用。请帮忙。提前致谢

Answer 1

我已经使用下面的动画方法解决了这个问题

let animation = CABasicAnimation(keyPath: "transform.translation.x")