正文
C# ASP.NET递归循环生成嵌套json结构树
小程序：扫一扫查出行【扫一扫了解最新限行尾号】
复制小程序
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": ''
}
]
}
]
}
]
}]
