策略模式应用之商场收费系统(C#源代码)

转自:http://blog.csdn.net/andylin02/archive/2008/11/14/3302034.aspx

using System;

namespace CashSystem

{

//线程类

class CRunMain

{

public static void ShowMessage()

{

Console.WriteLine("-----------------please input your choise: ------------");

Console.WriteLine("/t/t0. quite");

Console.WriteLine("/t/t1. pay cash noremally");

Console.WriteLine("/t/t2. pya cash in 8 rebate");

Console.WriteLine("/t/t3. pay cash in after 300 return 100");

Console.WriteLine("-------------------------------------------------------");

}

public static int Main()

{

CCashContext objCont = new CCashContext();

CCashSuper objCash = null;

while (true)

{

int nChoice = 0;

int nCount = 0;

double duMoney = 0.0;

double duPrice = 0.0;

ShowMessage();

nChoice = Convert.ToInt32(Console.ReadLine());

switch (nChoice)

{

case 0:

Console.WriteLine("press any key to quit!");

Console.Read();

return 0;

case 1:

objCash = new CCashNormal();

break;

case 2:

objCash = new CCashRebate(0.8);

break;

case 3:

objCash = new CCashReturn(300, 100);

break;

default:

objCash = null;

break;

}

if (null == objCash)

{

Console.WriteLine("input error!");

continue;

}

//set cash object

objCont.SetBehavior(objCash);

Console.WriteLine("please input price: ");

duPrice = Convert.ToDouble(Console.ReadLine());

Console.WriteLine("please input count: ");

nCount = Convert.ToInt32(Console.ReadLine());

duMoney = duPrice * nCount;

Console.WriteLine("the properly money you should pay is " + objCont.GetResult(duMoney));

}

}

};

//收费策略Context

class CCashContext

{

//设置策略行为，参数为具体的现金收费子类（正常，打折或返利）

public void SetBehavior(CCashSuper objCash)

{

this.m_objCash = objCash;

}

public double GetResult(double duMoney)

{

if (null == this.m_objCash)

{

Console.WriteLine("null == m_objCash");

return 0;

}

return this.m_objCash.AcceptCash(duMoney);

}

private CCashSuper m_objCash;

};

abstract class CCashSuper

{

public abstract double AcceptCash(double duMoney);

};

class CCashReturn:CCashSuper

{

public CCashReturn(double duCondition, double duReturn)

{

this.m_duCondition = duCondition;

this.m_duReturn = duReturn;

}

public override double AcceptCash(double duMoney)

{

if (duMoney > this.m_duCondition)

{

duMoney -= this.m_duReturn;

}

return duMoney;

}

private double m_duCondition = 0.0;

private double m_duReturn = 0.0;

};

class CCashNormal:CCashSuper

{

public override double AcceptCash(double duMoney)

{

return duMoney;

}

};

class CCashRebate:CCashSuper

{

public CCashRebate(double duRebate)

{

this.m_duRebate = duRebate;

}

public override double AcceptCash(double duMoney)

{

return duMoney * this.m_duRebate;

}

private double m_duRebate;

};

}