xml文件<?xml version="1.0" encoding="utf-8"?>
<Books>
<Book ID="1">
<Title>C#入门经典</Title>
<Price>95.00</Price>
</Book>
<Book ID="13">
<Title>C#从入门到精通</Title>
<Price>145.00</Price>
</Book>
<Book ID="4">
<Title>Java高级编程</Title>
<Price>165.00</Price>
</Book>
</Books>//添加xml节点private void addxml(){XmlDocument xmldoc = new XmlDocument();//加载xml文件xmldoc.Load(@"E:\Test\Test\tt.xml");//查找 根节点 BooksXmlNode root = xmldoc.SelectSingleNode("Books");//创建 子节点 BookXmlElement book = xmldoc.CreateElement("Book");book.SetAttribute("ID", "2");//设置子节点属性//创建 Book 子节点 TitleXmlElement title = xmldoc.CreateElement("Title");title.InnerText = "C#高级编程";//title 节点 添加到 root
            book.AppendChild(title);//创建 Book 子节点 PriceXmlElement price = xmldoc.CreateElement("Price");price.InnerText = "145.00";//price 节点 添加到 root
            book.AppendChild(price);//最后把book 节点添加到root
            root.AppendChild(book);//保存xmldoc.Save(@"E:\Test\Test\tt.xml");}//删除xml 节点private void deletexml(){XmlDocument xmldoc = new XmlDocument();//加载xml文件xmldoc.Load(@"E:\Test\Test\tt.xml");/*//查找到ID＝2的节点，删除book 下面的子节点，最后会留下一个空的<book></book>XmlNodeList nodelist = xmldoc.SelectNodes("//Books/Book[@ID=2]");//需了解xpathforeach (XmlNode n in nodelist){XmlElement xe = (XmlElement)n;//删除属性xe.RemoveAllAttributes();//删除节点xe.RemoveAll();}*///删除 book＝2 节点（包括book 节点）XmlNodeList nodelist = xmldoc.SelectNodes("//Books/Book[@ID=2]");//需了解xpathforeach (XmlNode n in nodelist){n.ParentNode.RemoveChild(n);}//保存xmldoc.Save(@"E:\Test\Test\tt.xml");}//修改xml 节点private void updatexml(){XmlDocument xmldoc = new XmlDocument();//加载xml文件xmldoc.Load(@"E:\Test\Test\tt.xml");//查找到ID＝2的节点，删除book 下面的子节点，最后会留下一个空的<book></book>XmlNodeList nodelist = xmldoc.SelectNodes("//Books/Book[@ID=3]");//需了解xpathforeach (XmlNode n in nodelist){XmlElement xe = (XmlElement)n;//XmlElement继承XmlNode//将属性 修改为13xe.SetAttribute("ID","13");//查找title节点XmlNode nn = n.SelectSingleNode("Title");nn.InnerText = "C#从入门到精通";}//保存xmldoc.Save(@"E:\Test\Test\tt.xml");}操作节点还有CDATA需要操作的XML文件：<Info>
<Link><![CDATA[<a href="http://www.52taiqiu.com">52台球网</a>]]></Link>
</Info>修改Link中的值XmlDocument xmldoc = new XmlDocument();
//加载xml文件
xmldoc.Load(@"E:\Test\Test\测试.xml");
XmlNode nameNode = xmldoc.SelectSingleNode("/Info/Link");
nameNode.InnerText = "";//如果是修改，需要把原先的值清空。
nameNode.AppendChild(xmldoc.CreateCDataSection("<a href=\"http://www.52taiqiu.com\">52台球网</a>"));
xmldoc.Save(@"E:\Test\Test\测试.xml");