C#操作XML方法:新增、修改和删除节点与属性:https://www.cnblogs.com/lip-blog/p/7652544.html
XElement与XmlElement相互转换的代码:https://blog.youkuaiyun.com/xieyufei/article/details/32708443
XML文件中,Node何Element有什么区别?: https://bbs.youkuaiyun.com/topics/20256523
XmlNode与XmlElement的区别总结:https://so.youkuaiyun.com/so/search/s.do?q=XElement与XmlElement&t=discuss&u=