如何在iOS13上制作阴影

Question

我在NSMutableAttributedString上设置阴影，它适用于其他版本的iOS，但不适用于iOS 13，下一个是我的代码

let shadow = NSShadow.init()
shadow.shadowColor = UIColor.red
shadow.shadowBlurRadius = 20

attr.addAttribute(NSAttributedString.Key.shadow, value: shadow, range: NSRange.init(location: 0, length: (text as NSString).length))

它在UILabel attributedText上运行良好，但在iOS13 上的CATextLayer字符串上运行不佳

Answer 1

iOS 14或更高版本的

let shadow = NSShadow.init()
shadow.shadowColor = UIColor.red
shadow.shadowBlurRadius = 20
attr.addAttribute(NSAttributedString.Key.shadow, value: shadow, range: NSRange.init(location: 0, length: (text as NSString).length))
subLayer.string = attr

ios 13或更早版本的

let shadow = NSShadow.init()
shadow.shadowColor = UIColor.red
shadow.shadowBlurRadius = 20
attr.addAttribute(NSAttributedString.Key.shadow, value: shadow, range: NSRange.init(location: 0, length: (text as NSString).length))
subLayer.shadowRadius = 20
subLayer.shadowColor = UIColor.red.cgColor
subLayer.shadowOpacity = 1
subLayer.string = attr