Interpreter 设计模式 实现代码

1、开发环境 vs2005 代码经测试无误

2、此代码根据李建忠老师的视频代码编写

3、注释一条令人迷惑的代码

4、实现YiExpression

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace Interpreter
{
class Program
{
static void Main(string[] args)
{
string roman = "五亿二十四万三千四百零二";

Context context = new Context(roman);
ArrayList tree = new ArrayList();
tree.Add(new GeExpression());
tree.Add(new ShiExpression());
tree.Add(new BaiExpression());
tree.Add(new QianExpression());
tree.Add(new WanExpression());
tree.Add(new YiExpression());

foreach(Expression exp in tree)
{
exp.Interpret(context);
}
Console.WriteLine("{0}={1}", roman, context.Data);

Console.Read();

}
}

public abstract class Expression
{
public Hashtable hstMap = new Hashtable();
public Expression()
{
hstMap.Add("一", 1);
hstMap.Add("二",2 );
hstMap.Add("三",3 );
hstMap.Add("四",4 );
hstMap.Add("五",5 );
hstMap.Add("六",6 );
hstMap.Add("七", 7);
hstMap.Add("八", 8);
hstMap.Add("九", 9);
}
public abstract string GetPostfix();
public abstract int GetMultiplier();
public virtual int GetLength()
{
return this.GetPostfix().Length + 1;
}

public virtual void Interpret(Context context)
{
if (context.Statement.Length==0)
{
return;
}
foreach (string key in hstMap.Keys)
{
int value = (int)hstMap[key];
if (context.Statement.EndsWith(key+this.GetPostfix()))
{
context.Data += value * this.GetMultiplier();
context.Statement = context.Statement.Substring(0, context.Statement.Length - this.GetLength());
}
if (context.Statement.EndsWith("零"))
{
context.Statement = context.Statement.Substring(0, context.Statement.Length-1);
}
}

}
}//class Expression

public class GeExpression:Expression
{
public override string GetPostfix()
{
return "";
}
public override int GetMultiplier()
{
return 1;
}
}
public class ShiExpression : Expression
{
public override string GetPostfix()
{
return "十";
}
public override int GetMultiplier()
{
return 10;
}
}
public class BaiExpression : Expression
{
public override string GetPostfix()
{
return "百";
}
public override int GetMultiplier()
{
return 100;
}
}
public class QianExpression : Expression
{
public override string GetPostfix()
{
return "千";
}
public override int GetMultiplier()
{
return 1000;
}
}

/// <summary>
/// 万和个十百千不一样
/// </summary>
public class WanExpression : Expression
{
public override string GetPostfix()
{
return "万";
}
public override int GetMultiplier()
{
return 10000;
}
public override void Interpret(Context context)
{
if (context.Statement.Length == 0)
{
return;
}

ArrayList tree = new ArrayList();
tree.Add(new GeExpression());
tree.Add(new ShiExpression());
tree.Add(new BaiExpression());
tree.Add(new QianExpression());

//foreach(string key in hstMap.Keys) //此行代码实属无用，个人愚见！！！！！！！！！！！！！！！！
{
if(context.Statement.EndsWith(this.GetPostfix()))
{
int temp = context.Data;
context.Data = 0;
context.Statement = context.Statement.Substring(0, context.Statement.Length - 1);

foreach(Expression exp in tree)
{
exp.Interpret(context);
}

context.Data = temp + this.GetMultiplier() * context.Data;
}
}

}

}

/// 亿和万类似
public class YiExpression : Expression
{
public override string GetPostfix()
{
return "亿";
}
public override int GetMultiplier()
{
return 100000000;
}
public override void Interpret(Context context)
{
if (context.Statement.Length == 0)
{
return;
}

ArrayList tree = new ArrayList();
tree.Add(new GeExpression());
tree.Add(new ShiExpression());
tree.Add(new BaiExpression());
tree.Add(new QianExpression());
tree.Add(new WanExpression());

// foreach (string key in hstMap.Keys)
{
if (context.Statement.EndsWith(this.GetPostfix()))
{
int temp = context.Data;
context.Data = 0;
context.Statement = context.Statement.Substring(0, context.Statement.Length - 1);

foreach (Expression exp in tree)
{
exp.Interpret(context);
}

context.Data = temp + this.GetMultiplier() * context.Data;
}
}

}

}

public class Context
{
private string statement;
private int data;
public Context(string statement)
{
this.statement=statement;
}
public string Statement
{
get { return statement; }
set { statement = value; }
}
public int Data
{
get { return data; }
set { data = value; }
}
}

}