XML文件是一种以简单文本格式存储数据的方式。下面介绍XML文件的几中基本操作。
1、新建XML文件

/// <summary>
        /// 1.新建XML文件
        /// </summary>
        public static  void CreateXML()
        {
            XmlDocument doc = new XmlDocument();
            //xml declaration (xml声明)
            XmlDeclaration declaration = doc.CreateXmlDeclaration("1.0","utf-8",null);
            XmlNode rootNode = doc.CreateNode(XmlNodeType.Element,"v","Games","www-microsoft-game");
            doc.AppendChild(rootNode);
            XmlNode node1 = doc.CreateNode(XmlNodeType.Element,"Game","www-microsoft-game");
            rootNode.AppendChild(node1);
            node1.Attributes.Append(doc.CreateAttribute("name")).InnerText = "文明3";
 
            node1.AppendChild(doc.CreateNode(XmlNodeType.Element,"Price",null)).InnerText = "100";
            XmlNode node2 = doc.CreateNode(XmlNodeType.Element,"www-microsoft-game");
            rootNode.AppendChild(node2);
            node2.Attributes.Append(doc.CreateAttribute("name")).InnerText = "帝国时代";
 
            node2.AppendChild(doc.CreateNode(XmlNodeType.Element,null)).InnerText = "300";
            doc.InsertBefore(declaration,doc.DocumentElement);
            doc.Save("game.xml");
        }

2、插入节点

/// <summary>
        /// 2.插入节点
        /// </summary>
        public static void InsertNode()
        {
            //1.加载XML document
            XmlDocument doc = new XmlDocument();
            doc.Load(@"game.xml");
            //Get the root element
            XmlNode  rootNode = doc.DocumentElement;
 
            //create the new game
            XmlNode newNode = doc.CreateNode(XmlNodeType.Element,"www-microsoft-game");
            rootNode.AppendChild(newNode);
            newNode.Attributes.Append(doc.CreateAttribute("name")).InnerText = "帝国时代X";
 
            newNode.AppendChild(doc.CreateNode(XmlNodeType.Element,null)).InnerText = "300";
 
            doc.Save("newgame.xml");
 
        }

3、删除节点

/// <summary>
        /// 3.删除节点
        /// </summary>
        public static void DeleteNode()
        {
            XmlDocument doc = new XmlDocument();
 
            doc.Load("newGame.xml");
 
            XmlNode root = doc.DocumentElement;
            if (root.HasChildNodes)
            {
                XmlNode game = root.LastChild;
                root.RemoveChild(game);
                doc.Save("newGame2.xml");
            }
 
        }

4、更新节点

/// <summary>
        /// 4.更新节点
        /// </summary>
        public static void UpdateNode()
        {
            XmlDocument doc = new XmlDocument();
            doc.Load("game.xml");
            XmlNode root = doc.DocumentElement;
            XmlNamespaceManager nsmgr =
new XmlNamespaceManager(
new XmlDocument().NaMetable);
            //建立Xml命名空间管理器对象 
            nsmgr.AddNamespace("v","www-microsoft-game");  
            //XmlNode updateNode = root.SelectSingleNode()
           XmlNode updateNode = doc.SelectSingleNode("v:Games/v:Game[@name='文明3']/Price",nsmgr);
 
           updateNode.InnerText =" 330";
           doc.Save("gamex.xml");
 
        }

参考资料：C# 操作XML之读取Xml浅析，http://developer.51cto.com/art/200908/144648.htm

C# 操作XML之建立Xml对象浅析 ，http://developer.51cto.com/art/200908/144652.htm

C#入门经典（第五版）中文版，第22章 XML p623-p645