Linq to XML同样是对原C#访问XML文件的方法的封装，简化了用xpath进行xml的查询以及增加，修改，删除xml元素的操作。

C#访问XML文件的常用类：XmlDocument，XmlElement，XmlAttribute，XmlNode，XmlText等;

Linq to XML 中的常用类 ：XDocument，XElement，XAttribute。

废话不多说了，直接上代码：

xml文件数据格式如下

public class DataBaseInfo
        {
            public string ID { get; set; }
            public string Company { get; set; }
            public string Server { get; set; }
            public string DataBase { get; set; }
            public string UserName { get; set; }
            public string Password { get; set; }
            private static XDocument doc = new XDocument();
            public static string filePath = ".\DataBaseInfo.xml";
            public DataBaseInfo() {
                doc = XDocument.Load(filePath);
            }
            public DataBaseInfo(string filepath):this()
            {
                filePath = filepath;
            }
            /// <summary>
            /// 增
            /// </summary>
            /// <returns></returns>
            public  bool Add()
            {
                XElement db = new XElement("DataBase",
                   new XAttribute("id", ID),
                   new XElement("company", new XAttribute("value",Company)),
                   new XElement("server", new XAttribute("value",Server)),
                   new XElement("database", new XAttribute("value",DataBase)),
                   new XElement("username", new XAttribute("value",UserName)),
                   new XElement("password", new XAttribute("value", Password))
                   );
                try
                {
                    //用XElement的Add方法
                    //XElement doc = XElement.Load(filePath);
                    //doc.Add(db);
                    //用XDocument的Add方法
                    doc.Element("DataBases").Add(db);
                    doc.Save(filePath);
                    return true;
                }
                catch
                {
                    return false;
                }
            }
            /// <summary>
            /// 删
            /// </summary>
            /// <param name="id"></param>
            /// <returns></returns>
            public static bool Remove(string id)
            {
                XElement xe = (from db in doc.Element("DataBases").Elements("DataBase") where db.Attribute("id").Value == id select db).Single() as XElement;
                try
                {
                    xe.Remove();
                    doc.Save(filePath);
                    return true;
                }
                catch
                {
                    return false;
                }
            }
            /// <summary>
            /// 改
            /// </summary>
            /// <returns></returns>
            public bool Modify()
            {
                XElement xe = (from db in doc.Element("DataBases").Elements("DataBase") where db.Attribute("id").Value.ToString() == ID select db).Single();
                try
                {
                    xe.Element("company").Attribute("value").Value = Company;
                    xe.Element("server").Attribute("value").Value = Server;
                    xe.Element("database").Attribute("value").Value = DataBase;
                    xe.Element("username").Attribute("value").Value = UserName;
                    xe.Element("password").Attribute("value").Value = Password;
                    doc.Save(filePath);
                    return true;
                }
                catch
                {
                    return false;
                }
            }
            /// <summary>
            /// 查
            /// </summary>
            /// <returns></returns>
            public List<DataBaseInfo> GetAll()
            {
                List<DataBaseInfo> dbs = (from db in doc.Element("DataBases").Elements("DataBase")
                                          select new DataBaseInfo
                                          {
                                              ID = db.Attribute("id").Value.ToString(),
                                              Company = db.Element("company").Attribute("value").Value.ToString(),
                                              Server = db.Element("server").Attribute("value").Value.ToString(),
                                              DataBase = db.Element("database").Attribute("value").Value.ToString(),
                                              UserName = db.Element("username").Attribute("value").Value.ToString(),
                                              Password = db.Element("password").Attribute("value").Value.ToString()
                                          }).ToList();
                return dbs;
            }

怎么样，如何对之前DOM方式访问XML熟悉的话， 是不是发现简单了不少呢？