C#面向对象设计模式纵横谈——16 Interpreter解释器模式
主讲：李建忠
来源：http://www.microsoft.com/china/msdn/events/webcasts/shared/webcast/consyscourse/CsharpOOD.aspx
1:
2: public class MainApp
3: {
4: static void Main()
5: {
6: sting roman="五千三百零九万六千四百五十二";
7:
8: Context context=new Context(roman);
9:
10: ArrayList tree=new ArrayList();
11: tree.Add(new GeExpresion());
12: tree.Add(new ShiExpresion());
13: tree.Add(new BaiExpresion());
14: tree.Add(new QianExpresion());
15: tree.Add(new WanExpresion());
16:
17: foreach(Expression exp in tree)
18: {
19: exp.Interpret(context);
20: }
21:
22: Console.WriteLine("{0}={1}",roman,context.Data);
23: }
24: }
25:
26: public class Context
27: {
28: private string statement;
29: private int data;
30:
31: public Context(statement)
32: {
33: this.statement=statement;
34: }
35:
36: public string Statment
37: {
38: get{return statement;}
39: set{statement=value;}
40: }
41:
42: public string Data
43: {
44: get{return data;}
45: set{data=value;}
46: }
47: }
48:
49: public abstract class Expression
50: {
51: protected Dictionary<string, int> table=new Dictionary<string, int>(9);
52: public Expression()
53: {
54: table.Add("一",1);
55: table.Add("二",2);
56: table.Add("三",3);
57: table.Add("四",4);
58: table.Add("五",5);
59: table.Add("六",6);
60: table.Add("七",7);
61: table.Add("八",8);
62: table.Add("九",9);
63: }
64:
65: public virtual void Interpret(Context context)
66: {
67: if(context.Statement.Length==0)
68: {
69: return;
70: }
71:
72: foreach(string key in table.Keys)
73: {
74: int value=table[key];
75:
76: if(context.Statement.EndsWith(key+GetPostfix()))
77: {
78: context.Data+=value*this.Multiplier();
79: context.Statement=context.Statement.Substring(0,context.Statement.Length-1);
80: }
81:
82: if(context.Statement.EndsWith("零"))
83: {
84: context.Statement=context.Statement.Substring(0,context.Statement.Length-this.Getlength());
85: }
86: }
87: }
88:
89: public abstract string GetPostfix();
90: public abstract int Multiplier();
91:
92: public virtual int GetLength()
93: {
94: return this.GetPostfix().Lenght+1;
95: }
96: }
97:
98: public class WanExpression:Expression
99: {
100: public override string GetPostfix()
101: {
102: return "万";
103: }
104:
105: public override void Interpret(Context context)
106: {
107: if(context.Statement.Length==0)
108: {
109: return;
110: }
111:
112: ArrayList tree=new ArrayList();
113: tree.Add(new GeExpresion());
114: tree.Add(new ShiExpresion());
115: tree.Add(new BaiExpresion());
116: tree.Add(new QianExpresion());
117:
118: foreach(string key in table.Keys)
119: {
120: int temp=context.Data;
121: context.Data=0;
122:
123: context.Statement=context.Statement.Substring(0,context.Statement.Length-1);
124:
125: foreach(Expression exp in tree)
126: {
127: exp.Interpret(context);
128: }
129:
130: context.Data=temp+this.Multiplier()*context.Data;
131: }
132: }
133:
134: public overrride Multiplier(){return 1000;}
135: }
136:
137: public class QianExpression:Expression
138: {
139: public override string GetPostfix()
140: {
141: return "千";
142: }
143:
144: public overrride int Multiplier(){return 1000;}
145: }
146:
147: public class BaiExpression:Expression
148: {
149: public override string GetPostfix()
150: {
151: return "百";
152: }
153:
154: public overrride int Multiplier(){return 100;}
155: }
156:
157: public class ShiExpression:Expression
158: {
159: public override string GetPostfix()
160: {
161: return "十";
162: }
163:
164: public overrride int Multiplier(){return 10;}
165: }
166:
167: public class GeExpression:Expression
168: {
169: public override string GetPostfix()
170: {
171: return "";
172: }
173:
174: public overrride int Multiplier(){return 1;}
175:
176: public override int GetLength()
177: {
178: return 1;
179: }
180: }
