Swift 从UITextView中删除重复单词

拥有UItextview的此委托后，我想删除此委托文本中已存在的标记词

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
    if text == " ",let lastWord = textView.text.components(separatedBy: " ").last, lastWord.hasPrefix("@"), let lastWordRange = (textView.text as NSString?)?.range(of: lastWord){
        if self.search(in: lastWord), searchDuplicate(this: lastWord) == 1  {
            let attributes = [NSForegroundColorAttributeName: UIColor.blue, NSFontAttributeName: self.textView.font!] as [String : Any]
            let attributedString = NSMutableAttributedString(string: lastWord, attributes: attributes)
            textView.textStorage.replaceCharacters(in:lastWordRange, with:attributedString)

        }else{
            if searchDuplicate(this: lastWord) > 1 {
                textView.text.removeSubrange(Range(uncheckedBounds: (lower: textView.text.index(textView.text.endIndex, offsetBy: -lastWord.characters.count ), upper: textView.text.endIndex)))
            }
            let realLW = lastWord.replacingOccurrences(of: "@", with: "")
            textView.textStorage.replaceCharacters(in:lastWordRange, with:realLW)
        }
    }
    return true
}

函数detect a word with@format并检查是否作为标记有效，但如果标记不是第一次输入，它将不会获得批准的格式，因为范围仅在第一次出现时检测到它，因此我必须删除它，但在textview的替换文本中。text all word失去了格式。因此，我如何检测重复删除的单词的范围

试试这个

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {

  if text == " " {
    let newText = removeDuplicates(text: textView.attributedText.string ?? "")
    let attributes = [NSForegroundColorAttributeName: UIColor.blue, NSFontAttributeName: self.textView.font!] as [String : Any]
    let attributedString = NSMutableAttributedString(string: newText, attributes: attributes)
    textView.attributedText = attributedString
  }
  return true
}

func removeDuplicates(text: String) -> String {
  let words = text.components(separatedBy: " ")
  let filtered = words.filter { $0.characters.first == "@" }
  return Array(Set(filtered)).joined()
}

---

先替换为.characters.first