private void Form1_Load(object sender, EventArgs e)

        {
                   //代码为TreeView添加子项

            treeView1.ContextMenuStrip = contextMenuStrip1;

            TreeNode tn = new TreeNode("默认");

            treeView1.Nodes.Add(tn);

        }

        private void button1_Click(object sender, EventArgs e)

        {
                  //代码为TreeView添加子项

            string text = textBox1.Text;

            TreeNode tn = new TreeNode(text);

            TreeNode tr = treeView1.SelectedNode;

            tr.Nodes.Add(tn);

        }

        private void 删除ToolStripMenuItem_Click(object sender, EventArgs e)

        {
                      //删除选中项

            treeView1.SelectedNode.Remove();

        }

<?xml version="1.0" encoding="utf-8" ?>

<Computers>

<Computer typr="222">

  <Name>LenovoY460</Name>

  <Price>5000</Price>

  <CPU>酷睿i3</CPU>

</Computer>

  <Computer typr="2223">

    <Name>Dell</Name>

    <Price>7000</Price>

    <CPU>酷睿i7</CPU>

  </Computer>

</Computers>

  XmlDocument doc = new XmlDocument();

            doc.Load("XMLFile1.xml");

            XmlNode xn = doc.DocumentElement;

            foreach (XmlNode item in xn.ChildNodes) {

                //foreach (XmlNode item1 in item.ChildNodes) {

                //    switch (item1.Name) {

                //        case "Name":

                //            Console.WriteLine("电脑的名字是：" + item1.InnerText);

                //            break;

                //        case "Price":

                //            Console.WriteLine("电脑的价格是：" + item1.InnerText);

                //            break;

                //        case "CPU":

                //              Console.WriteLine("电脑的CPU是：" + item1.InnerText);

                //            break;

                //    }

                //}

                Console.WriteLine(item.Attributes["typr"].Value);

                Console.WriteLine("电脑的名字是：" + item["Name"].InnerText);

                Console.WriteLine("电脑的Price是：" + item["Price"].InnerText);

                Console.WriteLine("电脑的CPU是：" + item["CPU"].InnerText);

            }

            Console.ReadKey();