public static List<T> GetDataList<T>(String sql, Func<IDataReader, T> build)

    {

        using (SqlConnection conn = GetSqlConnection())

        {

            SqlCommand cmd = new SqlCommand();

            cmd.Connection = conn;

            cmd.CommandText = sql;

            conn.Open();

            List<T> list = new List<T>();

            using (SqlDataReader reader = cmd.ExecuteReader())

            {

                while (reader.Read())

                {

                    T t = build(reader);

                    if (t==null) continue;

                    list.Add(t);

                }

                return list;

            }

        }

    }

protected void Init_PeopleChoice()

    {

        String sql = "Select Id,username From nodemanager where "+

          "isinfo=1 order by id desc";

        Id_UserName t = new Id_UserName();

        List<ListItem> list = SqlHelper.GetDataList(sql, Func < IDataReader, Id_UserName > builder);

    }

    protected Id_UserName builder(SqlDataReader reader)

    {

        Id_UserName t = new Id_UserName();

        t.id = reader.GetString(0).Trim().ToString();

        t.username = reader.GetString(1).Trim().ToString();

        return t;

    }

    class Id_UserName

    {

        public String id { get; set; }

        public String username { get; set; }

&n