分享一个递归无限级拼接Json的方法---ExtJs的TreePanel和TreeGrid均适用(Ef，Lambda,Linq,IQueryable,List)

 1 /// <summary>
 2         /// 得到树TreePanel的Json
 3         /// </summary>
 4         /// <returns></returns>
 5         public string GetAllLeftMenu4TreePanelJson()
 6         {
 7             StringBuilder allLeftMenuJsonStr = new StringBuilder();
 8             allLeftMenuJsonStr.Append("[");
 9             int normal = Convert.ToInt32(Common.Enum.DelFlagEnum.Normal);//lambda表达式中不可以有类型转换
10             List<AdminLeftMenuInfo> adminLeftMenuInfos = GetEntitesQueryable(m => m.DelFlag == normal).ToList();
11             foreach (var adminLeftMenuInfo in adminLeftMenuInfos)
12             {
13                 if (adminLeftMenuInfo.ParentId == 0)           //如果该元素的父ID为0   则是顶级元素
14                 {
15                     allLeftMenuJsonStr.Append("{");
16                     allLeftMenuJsonStr.Append("\"text\":\" " + adminLeftMenuInfo.PageName + " \"  ");
17                     allLeftMenuJsonStr.Append(",");
18 
19                     allLeftMenuJsonStr.Append("\"checked\":false");
20                     allLeftMenuJsonStr.Append(",");
21                     allLeftMenuJsonStr.Append("\"cls\":\"folder\"");
22 
23 
24                     List<AdminLeftMenuInfo> childrens = adminLeftMenuInfos.Where(m => m.ParentId == adminLeftMenuInfo.Id).ToList();
25                     if (childrens.Count != 0) //如果他还有儿子---拼接儿子
26                     {
27                         allLeftMenuJsonStr.Append(",");
28                         allLeftMenuJsonStr.Append("\"children\":");
29                         // var newChildrens=
30                         DoAppendChildJson4TreePanel(childrens, allLeftMenuJsonStr);
31 
32                     }
33 
34                     allLeftMenuJsonStr.Append("},");
35 
36                 }
37             }
38             allLeftMenuJsonStr.Remove(allLeftMenuJsonStr.Length - 1, 1);
39             allLeftMenuJsonStr.Append("]");
40             return allLeftMenuJsonStr.ToString();
41         }
42         /// <summary>
43         /// 用于全部TreePanel的递归子叶子的方法
44         /// </summary>
45         /// <param name="childrens">儿子作为参数</param>
46         /// <param name="allLeftMenuJsonStr">把需要继续拼接的Json字符串传进来</param>
47         private void DoAppendChildJson4TreePanel(List<AdminLeftMenuInfo> childrens, StringBuilder allLeftMenuJsonStr)
48         {
49             allLeftMenuJsonStr.Append("[");
50             foreach (var children in childrens)
51             {
52                 //判断children是否还有儿子，如果有为folder,如果没有儿子就是leaf,
53                 //并且checked=false;
54                 //   var son = GetEntitesQueryable(m => m.ParentId == children.Id);
55                 List<AdminLeftMenuInfo> son = GetEntitesQueryable(m => m.ParentId == children.Id).ToList();
56                 if (son.Count == 0)  //没有儿子了 那么他就是叶子
57                 {
58                     allLeftMenuJsonStr.Append("{");
59                     allLeftMenuJsonStr.Append("\"text\":\"" + children.PageName + "\"");
60                     allLeftMenuJsonStr.Append(",");
61                     allLeftMenuJsonStr.Append("\"leaf\":true");
62                     allLeftMenuJsonStr.Append(",");
63                     allLeftMenuJsonStr.Append("\"checked\":false");
64                     allLeftMenuJsonStr.Append("},");
65                 }
66                 else//有儿子 那么他就是文件夹
67                 {
68                     allLeftMenuJsonStr.Append("{");
69                     allLeftMenuJsonStr.Append("\"text\":\"" + children.PageName + "\"");
70                     allLeftMenuJsonStr.Append(",");
71                     allLeftMenuJsonStr.Append("\"cls\":\"folder\"");
72                     allLeftMenuJsonStr.Append(",");
73                     allLeftMenuJsonStr.Append("\"checked\":false");
74                     allLeftMenuJsonStr.Append(",");
75                     allLeftMenuJsonStr.Append("\"children\":");
76                     DoAppendChildJson4TreePanel(son, allLeftMenuJsonStr);    //如果还有儿子  那么就一直递归下去
77                     allLeftMenuJsonStr.Append("},");
78                 }
79 
80             }
81             allLeftMenuJsonStr.Remove(allLeftMenuJsonStr.Length - 1, 1);
82             allLeftMenuJsonStr.Append("]");
83         }