Asp.Net中调用存储过程并返回输出参数

  /// <summary>
         /// 调用存储过程返回参数
         /// </summary>
         /// <param name="orderId"></param>
         /// <param name="cancelOrderReson"></param>
         /// <returns></returns>
         private string[] CancelOrderProcedure(int orderId, string cancelOrderReson)
         {
             string constr = DbHelperSQL.connectionString;
             SqlConnection conn = new SqlConnection(constr);
             conn.Open();
             SqlCommand cmd = new SqlCommand();
             cmd.Connection = conn;
             cmd.CommandText = "Remy_Customer_CancelRedeemOrder";
             cmd.CommandType = CommandType.StoredProcedure;
             //参数一
             SqlParameter parameter_OrderId = new SqlParameter("@RedeemOrderId", SqlDbType.Int);
             parameter_OrderId.Direction = ParameterDirection.Input;
             parameter_OrderId.Value = orderId;
             //参数二
             SqlParameter parameter_OrderRemind = new SqlParameter("@RedeemOrderRemind", SqlDbType.NVarChar, );
             parameter_OrderRemind.Direction = ParameterDirection.Input;
             parameter_OrderRemind.Value = cancelOrderReson;

             SqlParameter parameter_ReturnCode = new SqlParameter("@ReturnCode", SqlDbType.NVarChar, );
             parameter_ReturnCode.Direction = ParameterDirection.Output;
             parameter_ReturnCode.Value = "";
             SqlParameter parameter_ReturnReason = new SqlParameter("@ReturnReason", SqlDbType.NVarChar, );
             parameter_ReturnReason.Direction = ParameterDirection.Output;
             parameter_ReturnReason.Value = "";

             cmd.Parameters.Add(parameter_OrderId);
             cmd.Parameters.Add(parameter_OrderRemind);

             cmd.Parameters.Add(parameter_ReturnCode);
             cmd.Parameters.Add(parameter_ReturnReason);
             try
             {
                 cmd.ExecuteNonQuery();
             }
             finally
             {
                 conn.Close();
             }
             string[] cancelResult = new String[] { parameter_ReturnCode.Value.ToString(), parameter_ReturnReason.Value.ToString() };
             return cancelResult;
         }