C# ASP.NET递归循环生成嵌套json结构树

1. 建立用来保存树结构数据的目标对象

    public  class TreeObject
    {
        public string name { get; set; }
        public string value { get; set; }
        public IList<TreeObject> children = new List<TreeObject>();
        public  void Addchildren(TreeObject node)
        {
            this.children.Add(node);
        }
    }

2.查询表获得数据源

        /// <summary>
        ///数据库的连接字符串
        /// </summary>
        private static readonly string connstr = @"server=.;database=userInfo;uid=sa;pwd=123456";;
 
        public DataTable getTable(string cmdText)
        {
            using (SqlConnection cnn = new SqlConnection(connstr))
            {
                using (SqlCommand comm = new SqlCommand(cmdText, cnn))
                {
                    comm.CommandType = CommandType.Text;
                    SqlDataAdapter da = new SqlDataAdapter();
                    da.SelectCommand = comm;
                    DataTable mytable = new DataTable();
                    da.Fill(mytable);
                    return mytable;
                }
            }
        }
 
        public DataTable GetDataTable()
        {
            string sql = @"select ID,NAME_SHORT,BELONGTO_ID
                            from UserInfo
                            order by BELONGTO_ID";
            DataTable dt = getTable(sql);
            return dt;
        }

3.递归循环生成树

       //全局变量用于保存数据
       public List<TreeObject> treeNodes = new List<TreeObject>();
 
        //建立树的递归方法
        /// </summary>
        /// <param name="dtSource">数据源</param>
        /// <param name="parentNode">父节点</param>
        /// <param name="parentID">节点的归属ID</param>
        public void BindTree(DataTable dtSource, TreeObject parentNode, string parentID)
        {
            DataRow[] rows = dtSource.Select(string.Format("BELONGTO_ID={0}", parentID));
            foreach (DataRow row in rows)
            {
                TreeObject tree = new TreeObject();
                tree.name = row["NAME_SHORT"].ToString();
                tree.value = row["ID"].ToString();
                //递归性质，函数内调用自身函数
                BindTree(dtSource, tree, row["ID"].ToString());
                //递归结束的终点条件
                if (parentNode == null)
                {
                    treeNodes.Add(tree);
                }
                else
                {
                    parentNode.children.Add(tree);
                }
            }
        }

4.调用

//调用SQL，获取数据源
DataTable dt = GetDataTable();
//调用递归函数，传入数据源，根节点
BindTree(dt, null, "");
//反序列化对象，生成json字符串
string jsonData = JsonConvert.SerializeObject(treeNodes);
return jsonData;

5.效果

[{
    "name": 'A',
    "value": '',
    "children": [{
            "name": 'B1',
            "value": '',
            "children": [{
                    "children": [],
                    "name": 'C',
                    "value": ''
                },
                {
                    "children": [],
                    "name": 'D',
                    "value": ''
                },
                {
                    "children": [],
                    "name": 'E',
                    "value": ''
                }
 
            ]
        },
        {
            "name": 'B2',
            "value": '',
            "children": [{
                    "children": [],
                    "name": 'F',
                    "value": ''
                },
                {
                    "children": [],
                    "name": 'G',
                    "value": ''
                }
            ]
        },
        {
            "name": 'B3',
            "value": '',
            "children": [{
                    "children": [],
                    "name": 'H',
                    "value": ''
                },
                {
                    "children": [],
                    "name": 'I',
                    "value": ''
                },
                {
                    "children": [],
                    "name": 'J',
                    "value": ''
                }
            ]
        },
        {
            "name": 'B4',
            "value": '',
            "children": [{
                    "children": [],
                    "name": 'K',
                    "value": ''
                },
 
                {
                    "name": 'L',
                    "value": '',
                    "children": [{
                            "children": [],
                            "name": 'L1',
                            "value": ''
                        },
                        {
                            "children": [],
                            "name": 'L2',
                            "value": ''
                        }
                    ]
                }
            ]
        }
 
    ]
}]