[HttpPost]
        public void Index(FormCollection F)
        {
            string xmlPath = Server.MapPath("~/A/") + "_Class.xml";
            XmlDocument doc;
            try 
            {
                string Id = F["Id"];
                string Name = F["Name"];
                string Age = F["Age"];
                string Sex = F["Sex"];
                string Phone=F["Phone"];

                if(!System.IO.File.Exists(xmlPath))
                {
                    //创建XML文档对象
                    doc = new XmlDocument();
                    //创建XML文档描述
                    XmlDeclaration del = doc.CreateXmlDeclaration("1.0", "utf-8", null);
                    //创建根节点
                    XmlNode root = doc.CreateNode(XmlNodeType.Element, "Class", null);
                     //在文档中添加描述
                    doc.AppendChild(del);
                    //在文档中添加根节点
                    doc.AppendChild(root);
                    doc.Save(xmlPath);
                }
                //创建XML文档对象
                doc = new XmlDocument();
                //读取指定的XML文件
                doc.Load(xmlPath);
                //读取XML中的根节点
                XmlElement element = doc.DocumentElement;
                //创建子节点
                XmlElement Stu = doc.CreateElement("Stu");
                //设置XML文本值
                Stu.InnerText = Name;
                //设置XML节点属性
                Stu.SetAttribute("Id", Id);
                Stu.SetAttribute("Sex", Sex);
                Stu.SetAttribute("Age", Age);
                Stu.SetAttribute("Phone", Phone);
                //在根节点中添加子节点
                element.AppendChild(Stu);

                //保存Xml文档到指定路径
                doc.Save(xmlPath);

                Response.Write("<script>alert(‘添加成功！‘);window.location.href = http://www.mamicode.com/‘/Home/Index‘;</script>");
            }
            catch (Exception ex)
            {
                Response.Write("<script>alert(‘添加失败！‘);window.location.href = http://www.mamicode.com/‘/Home/Index‘;</script>");
            }
            
        }


        public ActionResult SelAndDel(string id = "0")
        {
            if (id != "0")
            {
                //进行删除操作
                string xmlPath = Server.MapPath("~/A/") + "_Class.xml";
                XmlDocument doc = new XmlDocument();
                doc.Load(xmlPath);
                XmlElement element = doc.DocumentElement;
                XmlNode node = doc.SelectSingleNode(string.Format("/Class/Stu[@id=‘{0}‘]",id));
                node.ParentNode.RemoveChild(node);
                doc.Save(xmlPath);
            }
            else
            {
                string xmlPath = Server.MapPath("~/A/") + "_Class.xml";
                StringBuilder sb = new StringBuilder();
                XmlDocument doc = new XmlDocument();
                doc.Load(xmlPath);
                XmlElement element = doc.DocumentElement;
                //遍历根节点下的所有子节点
                foreach (XmlElement item in element.ChildNodes)
                {
                    sb.Append(string.Format(@"<tr class=‘odd gradeX‘>
                                            <td>{0}</td>
                                            <td>{1}</td>
                                            <td class=‘hidden-480‘>{2}</td>
                                            <td class=‘hidden-480‘>{3}</td>
                                            <td class=‘center hidden-480‘>{4}</td>
                                            <td><a href=http://www.mamicode.com/‘/Home/SelAndDel/{5}‘>删除>",
                                        item.Attributes["Id"].Value, item.InnerText,item.Attributes["Age"].Value,
                                        item.Attributes["Sex"].Value, item.Attributes["Phone"].Value, item.Attributes["Id"].Value)
                                        );
                }
                ViewBag.tableText = sb.ToString();
            }
            return View();
        }

@Html.Raw(ViewBag.tableText.ToString())//将在控制器中写的HTML代码字符串转换成HTML代码在前台显示执行

<?xml version="1.0" encoding="utf-8"?>
<Class>
  <Stu Id="1" Sex="女" Age="1" Phone="1">1</Stu>
  <Stu Id="0" Sex="女" Age="0" Phone="0">0</Stu>
</Class>