无限级分根据当前Id读取下级Id

using System;

using System.Collections;

using System.Configuration;

using System.Data;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Xml.Linq;

using System.Configuration;

using System.Data.SqlClient;

public partial class nextclassid : System.Web.UI.Page

{

protected static string connectionString = ConfigurationManager.AppSettings["ConnStr"].ToString();

protected void Page_Load(object sender, EventArgs e)

{

int classid = Convert.ToInt32(Request.QueryString["id"]);

DataList1.DataSource = GetListClass(classid);

DataList1.DataBind();

}

public DataTable GetListClass(int ClassId)

{

SqlConnection Conn = new SqlConnection(connectionString);

Conn.Open();

SqlDataAdapter sda = new SqlDataAdapter();

sda.SelectCommand = new SqlCommand("select * from ArticleClass", Conn);

//DataSet ds = new DataSet();

//sda.Fill(ds, "ArticleClass");

//DataTable DT = new DataTable();

//DT = (DataTable)ds.Tables["ArticleClass"];

DataTable DT = new DataTable();

sda.Fill(DT);

DataRow myrow;

DataTable mytab = new DataTable();

mytab.Columns.Add("Id");

mytab.Columns.Add("Title");

mytab.Clear();

for (int i = 0; i < DT.Rows.Count; i++)

{

if (ClassId == (int)DT.Rows[i]["ParentId"])

{

myrow = mytab.NewRow();

myrow[0] = DT.Rows[i]["Id"];

myrow[1] = DT.Rows[i]["Title"];

mytab.Rows.Add(myrow);

myrow.AcceptChanges();

}

}

if (mytab.Rows.Count == 0) mytab = GetListClass(0);

return mytab;

}

}