为何在ASP.NET中将数组赋值给Excel工作表的单元格上不成功？

以下代码试图用泛型取得数据库的数据后再转成数组，然后将数组赋值给Excel工作表的单元格，但不成功。请教大家应如何解决，谢谢!
public void ExcelMethod(string service)
        {
            SqlConnection cn = new SqlConnection(ConfigurationManager.ConnectionStrings["MyDB"].ConnectionString);

            SqlCommand cmd = new SqlCommand(
                    @"SELECT Id, Weight, Name, City, State, WebsiteUrl, Latitude, Longitude
              FROM Athlete
              WHERE (Weight = @Weight)", cn);

            cmd.Parameters.AddWithValue("Weight", service);

            List<AnAthlete> retrievedAthletes = new List<AnAthlete>();

            cn.Open();
            using (SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                while (dr.Read())
                {
                    retrievedAthletes.Add(new AnAthlete(dr.GetInt32(0),
                                                        dr.GetString(1),
                                                        dr.GetString(2),
                                                        dr.GetString(3),
                                                        dr.GetString(4),
                                                        dr.GetString(5),
                                                        dr.GetDouble(6),
                                                        dr.GetDouble(7)));
                }
            }
            rng = ws.get_Range("B5", "H10");
            rng.Value2 = retrievedAthletes.ToArray();
        }