一、问题描述
信用卡还款是银行系统的重要业务，业务流程说明如下：
-
用户有信用卡和储蓄卡，储蓄卡有查询余额和取款功能，信用卡能够查看账单金额、查看还款日和查看余额三个功能；
-
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。
二、代码
namespaceConsoleApplication3delegate
{
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;
publicCreditCard(intbillamount, intrepaymentday)
{
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 delegate void Depositrepayment(int a,int b);
public delegate void Creditrepayment();
public event Depositrepayment NotifyMoney;
public event Creditrepayment NotifyAmount;
public void Notify1(int a,int b)
{
if (NotifyMoney != null)
{
Console.WriteLine(“触发储蓄卡还款事件：”);
NotifyMoney(a,b);
}
}
public void Notify2()
{
if (NotifyAmount != null)
{
Console.WriteLine(“触发信用卡还款事件：”);
NotifyAmount();
}
}
//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。。。。。。”);
CreditCardDelegate.Depositrepayment call1 = new CreditCardDelegate.Depositrepayment(depositCard.Account);//储蓄卡扣款
CreditCardDelegate.Creditrepayment call2 = new CreditCardDelegate.Creditrepayment(card.repay);//信用卡账单清除
obj.NotifyMoney += call1;//事件绑定
obj.NotifyAmount += call2;
//执行事件,开始信用卡还款
obj.Notify1(card.getbillamount(), card.getrepaymentday());
obj.Notify2();
obj.NotifyMoney -= call1;//事件解绑
obj.NotifyAmount-= call2;
card.Display();
// 请在此处添加自己的代码
Console.WriteLine(“”);
}
Console.ReadLine();
}
}
}
三、结果测试
总结：
通过此次实验，体会到委托在程序设计中的重要性,他将方法当作另一个方法的参数来进行传递，这种将方法动态地赋给参数的做法。我对委托与事件的认识有了深一步了解。