private static void DoMenu(BillingManager manager, string input, List <BillingManager> managers) { int pl_RetVal = 0; switch (input) { case "1": pl_RetVal = manager.GetBalance(); break; case "2": Console.Write("충전할 캐시금액입력:"); int amt = Convert.ToInt32(Console.ReadLine()); pl_RetVal = manager.InsertCash(amt); break; case "3": Console.Write("환불할 캐시번호 입력:"); int cashno = Convert.ToInt32(Console.ReadLine()); pl_RetVal = manager.InsertCash(cashno); break; case "4": Console.Write("구매 할 아이템 번호 입력"); int itemNo = Convert.ToInt32(Console.ReadLine()); pl_RetVal = manager.PurchaseItem(itemNo); break; case "5": Console.Write("취소 할 구매 번호 입력"); int purchaseNo = Convert.ToInt32(Console.ReadLine()); pl_RetVal = manager.PurchaseCancelItem(purchaseNo); break; case "6": pl_RetVal = manager.PrintCashList(); break; case "7": pl_RetVal = manager.PrintItemList(); break; case "8": pl_RetVal = manager.PrintCashHistory(managers); break; case "9": pl_RetVal = manager.PrintItemPurchaseHistory(managers); break; } // Console.Clear(); if (pl_RetVal.Equals(0)) { Console.WriteLine("성공"); } else { Console.WriteLine("실패"); } }