How to make a shadow on iOS13

Question

I set shadow on NSMutableAttributedString, it works on other version of iOS but not iOS 13, the next is my code

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))

It works well on UILabel attributedText，but not works well on CATextLayer string On iOS13

Answer 1

iOS 14 or later

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 or earlier

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