XmlDocument doc = new XmlDocument();
XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", "GB2312", null);
doc.AppendChild(dec);
//创建一个根节点(一级)
XmlElement root = doc.CreateElement("First");
doc.AppendChild(root);
//创建节点(二级)
XmlNode node = doc.CreateElement("Seconde");
//创建节点(三级)
XmlElement element1 = doc.CreateElement("Third1");
element1.SetAttribute("Name", "Sam");
element1.SetAttribute("ID", "665");
element1.InnerText = "Sam Comment";
node.AppendChild(element1);
XmlElement element2 = doc.CreateElement("Third2");
element2.SetAttribute("Name", "Round");
element2.SetAttribute("ID", "678");
element2.InnerText = "Round Comment";
node.AppendChild(element2);
root.AppendChild(node);
doc.Save(@"d:\bb.xml");
Console.Write(doc.OuterXml);