C# 将数据库中01，0101 ，0102。。形成Tree

现将数据List  toDatatable

方法：

public static DataTable ToDataTable(IList list)
         {
             DataTable result = new DataTable();
             if (list.Count > 0)
             {
                 PropertyInfo[] propertys = list[0].GetType().GetProperties();
                 foreach (PropertyInfo pi in propertys)
                 {
                     result.Columns.Add(pi.Name, pi.PropertyType);
                 }
                 for (int i = 0; i < list.Count; i++)
                 {
                     ArrayList tempList = new ArrayList();
                     foreach (PropertyInfo pi in propertys)
                     {
                         object obj = pi.GetValue(list[i], null);
                         tempList.Add(obj);
                     }
                     object[] array = tempList.ToArray();
                     result.LoadDataRow(array, true);
                 }
             }
             return result;
         }在把DataTable 转成排好序的集合
  public static List<Data> CreatTree(DataTable dt)
         {


             var list = (from x
                        in dt.Rows.Cast<DataRow>()
                         group x by x["Code"].ToString().Length into g
                         select new { Key = g.Key, Items = g.ToList() }).OrderBy(x => x.Key);
             List<Data> DataRoot = new List<Data>();
             list.ToList()
                 .ForEach(x =>
                 {
                     if (x.Key == 2)
                     {
                         x.Items.ForEach(y => DataRoot.Add(new Data()
                         {
                             ID = y["Code"].ToString(),
                             EID = y["Id"].ToString(),
                             Name = y["Name"].ToString(),
                             Level = x.Key / 2 - 1
                         }));
                     }
                     else
                     {
                         x.Items.ForEach(y =>
                         {
                             Data data = null;
                             foreach (var item in DataRoot)
                             {
                                 data = item[y["Code"].ToString().Substring(0, y["Code"].ToString().Length - 2)];
                                 if (data != null) break;
                             }
                             if (data != null)
                             {
                                 data.Childs.Add(new Data()
                                 {
                                     ID = y["Code"].ToString(),
                                     EID = y["Id"].ToString(),
                                     Name = y["Name"].ToString(),
                                     Level = x.Key / 2 - 1
                                 });
                             }
                         });
                     }
                 });
             return DataRoot;
         }model：
  public class Data 
      public int Level { get; set; }
         public string ID { get; set; }
         public string EID { get; set; }
         public string Name { get; set; }
         public List<Data> Childs { get; set; }     public Data() { Childs = new List<Data>(); }


         public Data this[string id]
         {
             get
             {
                 if (ID == id) return this;
                 Data data = null;
                 if (Childs.Count > 0)
                 {
                     data = Childs.Where(x => x.ID == id).SingleOrDefault();
                     if (data == null)
                     {
                         foreach (var item in Childs)
                         {
                             data = item[id];
                             if (data != null) break;
                         }
                     }
                 }
                 return data;
             }
         }