崩溃替换NSAttributedString上的字符

Question

知道为什么会崩溃：

extension NSAttributedString {

    func replaceCharacters(inRange: NSRange, withString: String) -> NSAttributedString {
        let mutableString = mutableCopy() as! NSMutableAttributedString
        mutableString.replaceCharacters(in: inRange, with: withString)
        return mutableString
    }

}

let label = UILabel()
label.attributedText = NSAttributedString(string: "abcdef")
let string = label.attributedText?.replaceCharacters(inRange: NSRange(location: 1, length: 1), withString: "-")

但这不是吗？

let label = UILabel()
label.attributedText = NSAttributedString(string: "abcdef")

let mutableString = label.attributedText?.mutableCopy() as! NSMutableAttributedString
mutableString.replaceCharacters(in: NSRange(location: 1, length: 1), with: "-")
let string: NSAttributedString = mutableString

PS：我在第二个要点上做的就是从第一个要点复制replaceCharacters(inRange:withString:)内部的代码。

Answer 1

试试这个：

'

  

注意：请根据您的要求添加String addAttribute

Answer 2

试试这个，这会对你有帮助

斯威夫特3：

 let label = UILabel()
    override func viewDidLoad() {
        super.viewDidLoad()

        let attrString = NSMutableAttributedString(string: "abcdef")
        attrString.mutableString.replaceCharacters(in: NSRange(location: 1, length: 1), with: "-")

        label.attributedText = NSAttributedString(string: attrString.string)
        print(label.attributedText!)

    }