时间格式的问题

List<YhdSdk.Domain.Order.OrderInfo> allOrderInfoList = yhdGetNewTrade.getOrderList(DateTime.Now.AddMinutes(-shopModel.newTradeTime).ToString("yyyy-MM-dd hh:mm:ss"), DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss"), CommonConstant.STR_ORDER_WAIT_SEND, Common.MessageEventArgs.MAINMESSAGEBOX);