策略模式

如图所示，做一个简单的计算费用的winform程序。

public abstract class CashSuper
{
public abstract double AccpetCash(double money);
}

/// <summary>
/// 正常收费
/// </summary>
public class CashNormal : CashSuper
{
public override double AccpetCash(double money)
{
return money;
}
}

/// <summary>
/// 打折收费
/// </summary>
public class CashRebate : CashSuper
{
/// <summary>
/// 折扣
/// </summary>
private double moneyRebate;

public CashRebate(string moneyRebate)
{
this.moneyRebate = double.Parse(moneyRebate);
}
public override double AccpetCash(double money)
{
return money * moneyRebate;
}
}

/// <summary>
/// 返利收费
/// </summary>
public class CashReturn : CashSuper
{
/// <summary>
/// 满多少 返多少
/// </summary>
private double moeyCondition;
private double moeyReturn;

public CashReturn(string moeyCondition, string moeyReturn)
{
this.moeyCondition = double.Parse(moeyCondition);
this.moeyReturn = double.Parse(moeyReturn);
}

public override double AccpetCash(double money)
{
double result = money;
if (money >= moeyCondition)
result = money - Math.Floor(money / moeyCondition) * moeyReturn;
return result;
}
}

 

 

class CashContext
{
CashSuper cs = null;

public CashContext(string type)
{
switch (type)
{
case "正常收费":
cs = new CashNormal();
break;
case "满300返100":
cs = new CashReturn("300", "100");
break;
case "打8折":
cs = new CashRebate("0.8");
break;
}
}
public double GetResult(double money)
{
return cs.AccpetCash(money);
}
}

 

 

private void button1_Click(object sender, EventArgs e)
{
CashContext cc = new CashContext(cboType.SelectedItem.ToString());
double price = double.Parse(tbPrice.Text);
double count = double.Parse(tbCount.Text);
double total = price * count;
double result = cc.GetResult(total);
tbResult.Text = result.ToString();
}