创建一个新的XML文件

        private static XmlElement rootele;
        private static XmlElement xmlele;
        private static XmlNodeList nodelist;
        private static XmlNode xmln;
private static void CreateNewXMLFile()
        {
            string[,] book_arr = new string[,] {   { "English",  "101" }, 
                                                 { "History",  "102" }, 
                                                 { "Computer", "103" },
                                                 { "Algorithm","104" } };
            xmldoc = new XmlDocument();            
            xmln = xmldoc.CreateNode(XmlNodeType.XmlDeclaration,"","");
            xmldoc.AppendChild(xmln);
            //add root node
            rootele = xmldoc.CreateElement("","Books","");            
            xmldoc.AppendChild(rootele);
            
            for (int i = 0; i < book_arr.GetLength(0); i++)
            {
                //add node
                rootele = xmldoc.CreateElement("book");
                //add element
                xmlele = xmldoc.CreateElement("name");
                xmlele.InnerText = book_arr[i, 0].ToString();
                rootele.AppendChild(xmlele);
                //add element
                xmlele = xmldoc.CreateElement("sales");
                xmlele.InnerText = book_arr[i, 1].ToString();
                rootele.AppendChild(xmlele);

                xmldoc.ChildNodes.Item(1).AppendChild(rootele);
            }
            xmldoc.Save(@"C:\Users\v-alzhou\Desktop\Create a new XML file.xml");                                    
        }