public static void Islem(int islemSecimi, CardInfo info, IBank bank, int payId) { if (islemSecimi == 1) { Console.WriteLine(bank.Pay(info.Tutar, info.KrediKartNo)); } else if (islemSecimi == 2) { Console.WriteLine(bank.TriDPay(info.Tutar, info.KrediKartNo)); } else if (islemSecimi == 3) { Console.WriteLine(bank.Cancel(payId)); } else if (islemSecimi == 4) { Console.WriteLine(bank.Refund(payId)); } }