用DataTable 递归生成目录树!

  static DataColumn column = new DataColumn();
    static DataTable table = new DataTable();

      static DataRow MyRow;
 public static DataTable GetCategoryTree(WebInfoBase info)
    {
       DataTable dt = info.List(_DefaultDB, "", "[ID],[Title],[ParentID],[ChildNum],[Depth],[OrderNo]", "&version=", "[ID] ASC");
      
       if (table.Rows.Count > 0)
       {
           table.Columns.Clear();
           table.Rows.Clear();
       }
       CreateDataTable();
       GetTree(dt, "0", 0);
       return table;
    }
      public static void GetTree(DataTable dt, string pid, int blank)
      {
          string str = " ";
          DataView dv = new DataView(dt);
          dv.RowFilter = "ParentID = " + pid;
          if (blank > 0)
          {
              string s = "";
              if (blank == 1)
              {
                  str = "├";
              }
              for (int i = 2; i <= blank; i++)
              {
                  s = s + "  |  "+" "+" - ";
              }
              str = s + "├";
          }
          
          foreach (DataRowView drv in dv)
          {
              string id = drv["ID"].ToString();
              string Title = drv["Title"].ToString();
              string OrderNo = drv["OrderNo"].ToString();
              string ParentID = drv["ParentID"].ToString();
              string Depth = drv["Depth"].ToString();
              string ChildNum = drv["ChildNum"].ToString();
              
              MyRow = table.NewRow();
              MyRow["ID"] = int.Parse(id);
              MyRow["Title"] = str + Title;
              MyRow["OrderNo"] = int.Parse(OrderNo);
              MyRow["ParentID"] = int.Parse(ParentID);
              MyRow["Depth"] = int.Parse(Depth);
              MyRow["ChildNum"] = int.Parse(ChildNum);
              table.Rows.Add(MyRow);

              int n = int.Parse(Depth);
              //if (n <= 1)
              //{
                  n++;
              //}
              GetTree(dt, id, n);
          }
      }
         public static void CreateDataTable()
      {
          table.Columns.Clear();
          column = new DataColumn();
          column.DataType = System.Type.GetType("System.Int32");
          column.ColumnName = "ID";
          table.Columns.Add(column);

          column = new DataColumn();
          column.DataType = System.Type.GetType("System.Int32");
          column.ColumnName = "ParentID";
          table.Columns.Add(column);

          column = new DataColumn();
          column.DataType = Type.GetType("System.String");
          column.ColumnName = "Title";
          table.Columns.Add(column);

          column = new DataColumn();
          column.DataType = Type.GetType("System.Int32");
          column.ColumnName = "ChildNum";
          table.Columns.Add(column);

          column = new DataColumn();
          column.DataType = Type.GetType("System.Int32");
          column.ColumnName = "Depth";
          table.Columns.Add(column);

          column = new DataColumn();
          column.DataType = Type.GetType("System.Int32");
          column.ColumnName = "OrderNo";
          table.Columns.Add(column);
          //table.Columns.Clear();

      }