sql_存储过程中输出参数的写法

public System.Collections.Generic.List<Model.HKSJ_Main> LoadPageData(int pageIndex, int pageSize, out int total)
        {
            DataSet ds = new DataSet();

            SqlParameter totalParameter = new SqlParameter("@total", SqlDbType.Int);
            totalParameter.Direction = ParameterDirection.Output;
            //DbHelperSQL.RunProcedure()


            //如果用了输出参数，那么就用SqlDataAdapter就可以了，用sqlDataReader时候拿不到输出参数的值。
            using (SqlConnection conn = new SqlConnection(DbHelperSQL.connectionString))
            {
                //conn.Open();
                using (SqlDataAdapter adapter = new SqlDataAdapter("P_LoadPageData", conn))
                {
                    adapter.SelectCommand.Parameters.Add(new SqlParameter("@pageIndex", pageIndex));
                    adapter.SelectCommand.Parameters.Add(new SqlParameter("@pageSize", pageSize));
                    
                    adapter.SelectCommand.CommandType = CommandType.StoredProcedure;
                    
                    //输出参数的用法
                    adapter.SelectCommand.Parameters.Add(totalParameter);

                    adapter.Fill(ds);
                }
            }
            total = (int)totalParameter.Value;//拿到输出参数的值

            return this.DataTableToList(ds.Tables[0]);

        }