迅速的IOS TextArea我可以从偏移量或光标中删除文本

Question

var currenTextCount = 0
func textViewDidChange(_ textView: UITextView) {
    currentTextCount = currentTextCount+1
}

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {


    let startPosition: UITextPosition = writeArea.beginningOfDocument

    let selectedRange: UITextRange = writeArea.selectedTextRange!

    let cursorPosition = writeArea.offset(from: startPosition, to: selectedRange.start)

    i don't know
}

我希望只要currenTextCount即可删除cursorPosition上的文本

或

在左侧＃和右侧空格之间删除文本

我不知道怎么办

Answer 1

  let newPosition:UITextPosition! = writeArea.position(from: selectedRange.start, offset: -currenTextCount)
  let nowPosition:UITextPosition! = writeArea.position(from: selectedRange.start, offset: 0)
  let tagRange:UITextRange! = writeArea.textRange(from: newPosition, to: nowPosition)
        writeArea.replace(tagRange, withText: selectedTag)
  writeArea.replace(tagRagne, withText: "String")