C# 操作XML

－、XMLTextWriter用法

using (System.IO.MemoryStream stream = new System.IO.MemoryStream())
            {
                //System.Xml.XmlTextWriter writer = new System.Xml.XmlTextWriter(stream, null);
                System.Xml.XmlTextWriter writer = new System.Xml.XmlTextWriter(Server.MapPath("userInfo.xml"), System.Text.Encoding.UTF8);

                writer.Formatting = System.Xml.Formatting.Indented;
                writer.WriteStartDocument(true);

                writer.WriteStartElement("PP");
                writer.WriteStartElement("X");
                writer.WriteString("1");
                writer.WriteEndElement();
                writer.WriteStartElement("Y");
                writer.WriteString("1");
                writer.WriteEndElement();
                writer.WriteStartElement("Name");
                writer.WriteString("fan");
                writer.WriteEndElement();
                writer.WriteEndElement();
                writer.Flush();
                writer.Close();
            }

二、XMLDocument用法

            XmlDocument xmldoc;
            XmlNode xmlnode;
            xmldoc = new XmlDocument();

            xmlnode = xmldoc.CreateNode(XmlNodeType.XmlDeclaration, "", "");
            xmldoc.AppendChild(xmlnode); 
            //加入XML的声明段落,<?xml version="1.0" encoding="utf-8"?>
            //xmlnode = xmldoc.CreateXmlDeclaration("1.0", "utf-8", null);
            //xmldoc.AppendChild(xmlnode);
            //加入一个根元素
            xmldoc.AppendChild(xmldoc.CreateElement("", "Menu", ""));

            foreach (ComponentArt.Web.UI.MenuItem mi in Menu2.Items)
            {
                if (mi.Enabled && mi.Visible)
                {
                    XmlElement xmlelem;
                    xmlelem = xmldoc.CreateElement("Item");
                    xmlelem.SetAttribute("title", string.Format("{0}", mi.Text));

                    if (string.IsNullOrEmpty(mi.NavigateUrl))
                        xmlelem.SetAttribute("url", string.Format("{0}", mi.Items[0].NavigateUrl));
                    else
                        xmlelem.SetAttribute("url", string.Format("{0}", mi.NavigateUrl));

                    xmldoc.ChildNodes.Item(1).AppendChild(xmlelem);
                }
            }

            xmldoc.Save(Request.PhysicalApplicationPath + @"data.xml");
            string xmlContent= xmldoc.OuterXml;

另外读取的话，用XMLTextReader很方式，也是只进读取，性能据说比较ＯＫ!
    三、XMLTextReader用法

            string targer;
            XmlDocument xmldoc = new XmlDocument();
            xmldoc.Load("userInfo.xml");
            byte[] bytes = System.Text.UTF8Encoding.UTF8.GetBytes(xmldoc.OuterXml);
            using (System.IO.MemoryStream stream = new System.IO.MemoryStream(bytes))
            {
                using (XmlTextReader reader = new XmlTextReader(stream))
                {
                    while (reader.Read())
                    {
                        if (!reader.IsEmptyElement && reader.NodeType == XmlNodeType.Element)
                        {
                            switch (reader.LocalName)
                            {
                                case "X":
                                    targer = reader.ReadString();
                                    break;
                            }
                        }
                    }
                }
            }

另外，XML的一个应用是序列化，要用到把字符串转化成byte数组，方法：
   byte[] bytes = System.Text.UTF8Encoding.UTF8.GetBytes(XmlContent); 
相对的，把byte数组转化为字符串的方法则为：
　string XmlContent = System.Text.UTFEncoding.UTF8.GetString(bytes);
这样方便了吧，把想存的东东转化为byte数组，然后压缩一下，网络传输的话也应该很ＯＫ了吧