请使用委托与事件实现下列功能：用户可自由设置信用卡还款关联的储蓄卡，当还款日到期时进行账单金额的自动划扣；请注意事件主要是设计什么时候启动委托，委托的主要目的是设置还款的储蓄卡为避免设计出现偏差，给出了部分功能代码，请在此基础上进行开发。

namespace ConsoleApplication3delegate

{

class DepositCard

{

public int amount;

public void Display()

{

Console.WriteLine("储蓄卡余额为：{0}", amount);

}

public void Account(int balance,int payday)

{

amount += balance;

Console.WriteLine("今天是本月的｛0｝，取款｛1｝，储蓄卡余额为：{2}。", DateTime.Today.Day,balance,amount);

}

}

class CreditCard

{

private int billamount;

private int repaymentday;

public CreditCard(int billamount, int repaymentday)

{

this.billamount = billamount;

this.repaymentday = repaymentday;

}

public int getbillamount() {return billamount;}

public int getrepaymentday() { return repaymentday;}

public void Display(){Console.WriteLine("信用卡余额为：{0}", billamount);}

}

class CreditCardDelegate

{

public int billamount;

public int repaymentday;

请在此处添加自己的代码

}

class Program

{

static void Main(string[] args)

{

DepositCard depositCard = new DepositCard();

depositCard.amount = 10000;

CreditCard creditCard1 = new CreditCard(-2000,9);

CreditCard creditCard2 = new CreditCard(-3000, 13);

CreditCard creditCard3 = new CreditCard(-5000, 29);

depositCard.Display(); Console.WriteLine("");

List<CreditCard> Cards = new List<CreditCard>();

Cards.Add(creditCard1); Cards.Add(creditCard2); Cards.Add(creditCard3);

foreach (CreditCard card in Cards)

{

Console.WriteLine("信用卡开始执行委托还款。。。。。。");

请在此处添加自己的代码

Console.WriteLine("");

}

Console.ReadLine();

}

}

}

首先在CreditCradDelegate类中对委托和事件进行定义

public delegate void Call(int billamount,int repaymentday);//定义委托

public event Call notifycredit;//定义事件

public void Notify()

{

//当日日期与还款日期相等且信用卡欠款时我们才会进行还款

if(DateTime.Today.Day==repaymentday && billamount<0)

{

Console.WriteLine("还款成功！");

notifycredit(billamount,repaymentday);

}

else

{

Console.WriteLine("还款失败！");

}

}

主程序中测试代码

card.Display();//每次对信用卡还款前查询储蓄余额

CreditCardDelegate CreditDelegate = new CreditCardDelegate();//委托的对象

CreditDelegate.billamount=card.getbillamount();//通过CreditCard对象getbillamount公有成员函数将私有成员传给委托对象公有成员billamount

CreditDelegate.repaymentday=card.getrepaymentday();//通过CreditCard对象getrepaymentday公有成员函数将私有成员传给委托对象公有成员repaymentday

CreditDelegate.notifycredit += new CreditCardDelegate.Call(depositCard.Account);//订阅该事件 通过DepositCard对象委托来执行对储蓄卡的取款并对信用卡还款

CreditDelegate.Notify();

depositCard.Display();//每次对信用卡执行操作后显示储蓄卡余额

总结

1.本次实验将委托与事件应用到实际的事情中，我更加熟悉了类的调用以及委托事件的用法。

2.实验过程中我发现自己对于委托和事件之间调用的规则不是很理解，对于事件的触发机制、参数如何传递的也不熟悉，写代码的过程中遇到了很多困难，在以后的写代码过程中要加强自己将理论应用于实际事情中的能力。（借鉴Aftersupper及Wacke_Tiny）