实在不会做了。。请求援助

题目列表及要求如下：
①Xml文件的读写、解析
a.现有一个树形结构的XML文件
b.将XML文件中的节点，以同样的结构关系，用TreeView控件显示在窗体中
c.控件中的每个树节点需要显示XML中的<name>…</name>卷标的文字，其余XML卷标的属性也要能够通过控件中的树节点获得
d.显示完成后，再将控件中的树按原格式重新生成新的XML文件，即将数据导出
e.要有面向对象思想
f.Winform实现


[解决办法]

C# code

 #region 判断某XML存不存在        /// <summary>        /// 判断某XML存不存在        /// </summary>        /// <param name="path">文件路径</param>        /// <returns>布尔值</returns>        public bool TheXmlIsExist(string path)        {            return File.Exists(path);                    }        #endregion        #region  读取一个XML文件，返回一个DataSet        /// <summary>        /// 读取一个XML文件，返回一个DataSet        /// </summary>        /// <param name="path">Xml文件路径</param>        /// <returns>把xml文件读成DataSet取出</returns>        public DataSet ReadTheXmlAndReturnDataSet(string path)        {            try            {                DataSet ds = new DataSet();                ds.ReadXml(path);                return ds;            }            catch (Exception e)            {                throw e;            }        }        #endregion
[解决办法]
不会做，先做简单的习题。
[解决办法]
[c#]

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace TreeWpf
{
   /// <summary>
   /// Window1.xaml 的交互逻辑
   /// </summary>
   ///  

   public partial class Window1 : Window
   {
       List<Info> MyInfoList = new List<Info>();
       public Window1()
       {
           InitializeComponent();
           MyInfoList = GetForumData();
           AddTreeNode(0, null);
          // MytreeView.ItemsSource = MyInfoList;

       }
       private void AddTreeNode(int parentID, TreeViewItem treeViewItem)
       {
           List<Info> result = (from forumInfo in MyInfoList
                                     where forumInfo.ParendID == parentID
                                select forumInfo).ToList<Info>();

           if (result.Count > 0)
           {
               foreach (Info Row in result)
               {
                   TreeViewItem objTreeNode = new TreeViewItem();
                   objTreeNode.Header = Row.ForumName;
                   objTreeNode.DataContext = Row;

                   //此样式将会添加的所有叶子结点上
                   //objTreeNode.ItemContainerStyle = this.Resources["RedItemStyle"] as Style;

                   //添加根节点
                   if (treeViewItem == null)
                   {
                       MytreeView.Items.Add(objTreeNode);
                   }
                   else
                   {
                       treeViewItem.Items.Add(objTreeNode);
                   }
                   AddTreeNode(Row.ForumID, objTreeNode);
               }
           }
       }
       public List<Info> GetForumData()
       {
           List<Info> forumList = new List<Info>();
           forumList.Add(new Info() { ForumID = 1, ParendID = 0, ForumName = "笔记本版块" });
           forumList.Add(new Info() { ForumID = 2, ParendID = 0, ForumName = "台式机版块" }); 
 

           forumList.Add(new Info() { ForumID = 3, ParendID = 1, ForumName = "Dell笔记本" });
           forumList.Add(new Info() { ForumID = 4, ParendID = 1, ForumName = "IBM笔记本" });
           forumList.Add(new Info() { ForumID = 5, ParendID = 4, ForumName = "IBM-T系列" });
           forumList.Add(new Info() { ForumID = 6, ParendID = 4, ForumName = "IBM-R系列" });

           forumList.Add(new Info() { ForumID = 7, ParendID = 2, ForumName = "联想台式机" });
           forumList.Add(new Info() { ForumID = 8, ParendID = 2, ForumName = "方正台式机" });
           forumList.Add(new Info() { ForumID = 9, ParendID = 2, ForumName = "HP台式机" });
           forumList.Add(new Info() { ForumID = 10, ParendID = 7, ForumName = "联想家悦H系列" });
           forumList.Add(new Info() { ForumID = 11, ParendID = 7, ForumName = "联想IdeaCentre系列" });

           return forumList;
       }

       private void MytreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
       {
           TreeView item0 = sender as TreeView;
           TreeViewItem item = e.NewValue as TreeViewItem;
           Info con = item.DataContext as Info;

           DetailsPanel.DataContext = con;

       }
   }
   public class Info
   {
       public int ForumID { get; set; }
       public int ParendID { get; set; }
       public string ForumName { get; set; }
   }
}
[/c#]
[解决办法]
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C# code

 #region 判断某XML存不存在
        /// <summary>
        /// 判断某XML存不存在
        /// </summary>
        /// <param name="path">文件路径</param>
        /// <returns>布尔值</returns>
        public bool Th……