iOS TextFiled 字数限制时 中文输入适配问题

1、添加文本变化通知

NotificationCenter.default.addObserver(self, selector: #selector(textDidChange), name: UITextField.textDidChangeNotification, object: self)

2、监听文字改变

//MARK - 监听文字改变
@objc func textDidChange() {
    if self.text == nil {
        return
    }
    // 限制长度
    if self.markedTextRange == nil {
        if self.maxLength != nil && self.maxLength! > 0 {
            if (self.text!.count) > (self.maxLength)! {
                let subString = self.text!.id_subString(to: (self.maxLength)!)
                self.text = subString
            }
        }
    }
}