简易文件夹无限级，使用递归重构层级列表

 1      /// <summary>
 2      /// 文件夹实体
 3      /// </summary>
 4      public class Folder
 5      {
 6          /// <summary>
 7          /// 文件夹ID
 8          /// </summary>
 9          public int id { get; set; }
10          /// <summary>
11          /// 文件夹名称
12          /// </summary>
13          public string name { get; set; }
14          /// <summary>
15          /// 父级ID
16          /// </summary>
17          public int folder_parent_id { get; set; }
18     }

 1         /// <summary>
 2         /// 重构文件夹层级列表
 3         /// </summary>
 4         /// <param name="listSource">源数据</param>
 5         /// <param name="pId">父级ID</param>
 6         /// <param name="count">添加元素的次数</param>
 7         /// <param name="levelNum">当前层级</param>
 8         /// <param name="listResult">返回结果集</param>
 9         private void RefactorFolderLevelList(List<Folder> listSource, int pId, int count, List<int> levelNum, List<Folder> listResult)
10         {
11             var len_source = listSource.Count();
12             if (count < len_source)
13             {
14                 var tmp_list = listSource.Where(m => m.folder_parent_id == pId);
15                 var len_tmp_list = tmp_list.Count();
16                 bool addFlag = true;
17                 int level = levelNum.Count();
18                 int i = 0;
19                 foreach (var item in tmp_list)
20                 {
21                     i++;
22                     item.name = FillString(level, "——") + item.name;
23                     var model = listResult.Where(m => m.id == item.id).FirstOrDefault();
24                     if (pId == 0 && model != null)
25                         continue;
26                     else
27                         listResult.Add(item);
28                     ++count;
29                     if (listSource.Where(m => m.folder_parent_id == item.id).Count() > 0)
30                     {
31                         if (!levelNum.Contains(item.id) && addFlag)
32                         {
33                             addFlag = false;
34                             levelNum.Add(item.id);
35                         }
36                         RefactorFolderLevelList(listSource, item.id, count, levelNum, listResult);
37                     }
38                     else
39                     {
40                         if (i < len_tmp_list)
41                             continue;
42                         levelNum = new List<int>();
43                         RefactorFolderLevelList(listSource, 0, count, levelNum, listResult);
44                     }
45                 }
46             }
47         }
48         /// <summary>
49         /// 字符串填充
50         /// </summary>
51         /// <param name="n">填充的次数</param>
52         /// <param name="str">需要填充的字符串</param>
53         /// <returns></returns>
54         private string FillString(int n, string str)
55         {
56             StringBuilder ret = new StringBuilder();
57             for (int i = 0; i < n; i++)
58             {
59                 ret.Append(str);
60             }
61             return ret.ToString();
62         }

效果图：