基本方法写XML文档

class Customer
    {
        private string firstName, lastName, emailAddress;

        public string FirstName
        {
            get { return firstName; }
            set { firstName = value; }
        }

        public string LastName
        {
            get { return lastName; }
            set { lastName = value; }
        }

        public string EmailAddress
        {
            get { return emailAddress; }
            set { emailAddress = value; }
        }
    }

public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private List<Customer> CreateCustomer()
        {
            List<Customer> result = new List<Customer>{
                new Customer{FirstName="Tom",LastName="James",EmailAddress="aaa@qq.com"},
                new Customer{FirstName="Helen",LastName="Christina",EmailAddress="bbb@qq.com"},
                new Customer{FirstName="Meimei",LastName="Han",EmailAddress="ccc@qq.com"}
            };
            return result;         
        }

        public void CreateXML()
        {
            string path = Environment.CurrentDirectory + @"\data.xml";
            List<Customer> customers = CreateCustomer();

            XmlDocument customerXml = new XmlDocument();
            XmlElement root = customerXml.createElement_x_x("Customers");                 
            customerXml.AppendChild(root);                                           

            foreach (Customer c in customers)
            {
                XmlElement element = customerXml.createElement_x_x("Customer");         
               
                XmlElement FirstNameElement = customerXml.createElement_x_x("FirstName"); 
                FirstNameElement.InnerText = c.FirstName;
                element.AppendChild(FirstNameElement);

                XmlElement LastNameElement = customerXml.createElement_x_x("LastName");  
                LastNameElement.InnerText = c.LastName;
                element.AppendChild(LastNameElement);

                XmlElement AddressElement = customerXml.createElement_x_x("Address");    
                AddressElement.InnerText = c.EmailAddress;
                element.AppendChild(AddressElement);

                root.AppendChild(element);                                            
            }

            customerXml.Save(path);
         }
       

        private void btnCreateXML_Click(object sender, EventArgs e)
        {
            CreateXML();
        }
    }