สอบถามการใช้ DropDownlist DataSource หน่อยครับ asp.net c#

string mysqlcon = "Server=localhost;User Id=root; Password=root; Database=atpservicemotion; Pooling=false";
                        using (MySqlConnection cn = new MySqlConnection(mysqlcon))
                        {
                            MySqlDataAdapter adp = new MySqlDataAdapter("SELECT Email,namegroup FROM listgroup WHERE Email = '" + strUser + "'", cn);
                            DataTable dt = new DataTable();
                            adp.Fill(dt);
                            if (dt.Rows.Count > 0)
                            {
                                DropDownList1.DataSource = dt;
                                DropDownList1.DataTextField = "namegroup";
                                DropDownList1.DataValueField = "Email";
                                DropDownList1.DataBind();
                            }
                        }