直接创建一个XmlDocument文档

XML 文件: 

<?xml version="1.0" encoding="utf-8"?>
<CategoryList>
<Category ID="01">
<MainCategory>XML</MainCategory>
<Description>This is a list my XML articles.</Description>
<Active>true</Active>
</Category>
</CategoryList>
代码如下: 
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Xml" %>
<%@ Page Language="C#" Debug="true" %>
<script  runat="server">
void Page_Load(object sender, System.EventArgs e){
if(!Page.IsPostBack){
XmlDocument xmlDoc = new XmlDocument();
// Write down the XML declaration
XmlDeclaration xmlDeclaration = xmlDoc.CreateXmlDeclaration("1.0","utf-8",null);
// Create the root element
XmlElement rootNode  = xmlDoc.CreateElement("CategoryList");
xmlDoc.InsertBefore(xmlDeclaration, xmlDoc.DocumentElement);
xmlDoc.AppendChild(rootNode);
// Create a new <Category> element and add it to the root node
XmlElement parentNode  = xmlDoc.CreateElement("Category");
// Set attribute name and value!
parentNode.SetAttribute("ID", "01");
xmlDoc.DocumentElement.PrependChild(parentNode);
// Create the required nodes
XmlElement mainNode  = xmlDoc.CreateElement("MainCategory");
XmlElement descNode  = xmlDoc.CreateElement("Description");
XmlElement activeNode  = xmlDoc.CreateElement("Active");
// retrieve the text
XmlText categoryText= xmlDoc.CreateTextNode("XML");
XmlText descText  = xmlDoc.CreateTextNode("This is a list my XML articles.");
XmlText activeText  = xmlDoc.CreateTextNode("true");
// append the nodes to the parentNode without the value
parentNode.AppendChild(mainNode);
parentNode.AppendChild(descNode);
parentNode.AppendChild(activeNode);
// save the value of the fields into the nodes
mainNode.AppendChild(categoryText);
descNode.AppendChild(descText);
activeNode.AppendChild(activeText);
// Save to the XML file
xmlDoc.Save( Server.MapPath("categories.xml"));
Response.Write("XML file created");
}
}
</script>