CodeDom系列二---程序基本结构--符号三角形问题

2010-06-20 14:02 破狼阅读(4375) 评论(12) 编辑收藏举报

昨天一个同学叫我帮编写一个符号三角形的c代码，今天就把它改写成用CodeDom生成的c#代码。

符号三角形：在一组字符串里（只有用空格分割的+或者-组成的字符串），在每次的相邻的两个符号比较，如果相同就在中间空格插入+,否则就插入-。一直运行到字符串里只有一个+或者-时停止，输出的字符串为符号三角形。

由于是CodeDom些列，所以先介绍几个CodeDom表达式：

1：CodeConditionStatement：判断语句即是if（condition）{} else{}，看最全的那个构造函数：
public CodeConditionStatement(
CodeExpression condition,//条件
CodeStatement[] trueStatements,//为true的语句体
CodeStatement[] falseStatements//为false语句体
)
2：CodeIterationStatement()：表示 for 语句或语句块内的循环（使用测试表达式作为继续循环的条件）：
在codedom中没有提高while和dowhile但是For已经够用的
public CodeIterationStatement(
CodeStatement initStatement,//for初始化
CodeExpression testExpression,//条件表达式
CodeStatement incrementStatement,//for变化体，增或减
CodeStatement[] statements//循环体
)
3：CodeBinaryOperatorExpression：表示一个表达式，该表达式包含在两个表达式间进行的二进制运算,
public CodeBinaryOperatorExpression(
CodeExpression left,//表达式左边
CodeBinaryOperatorType op,//操作符
CodeExpression right//表达式右边
)
4：CodeArrayIndexerExpression：表示对数组的索引的引用：
public CodeArrayIndexerExpression(
CodeExpression targetObject,//数组对象
CodeExpression[] indices//下标
)
其他参见CodeDOM 快速参考：msdn.microsoft.com/zh-cn/library/f1dfsbhc(VS.80).aspx
code：
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public CodeNamespace CreateNameSpace()
{
public CodeNamespace CreateNameSpace()
{
//Test
CodeMemberMethod test = new CodeMemberMethod();
test.Name = "Test";
test.Attributes = MemberAttributes.Public | MemberAttributes.Final;
test.Statements.Add(new CodeVariableDeclarationStatement(typeof(char[]), "ch",

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new CodeMethodInvokeExpression(new CodePrimitiveExpression("+ - + - + + - -"), "ToCharArray",

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new CodeExpression[] { })));
test.Statements.Add(new CodeMethodInvokeExpression(new CodeMethodReferenceExpression

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(new CodeThisReferenceExpression(), "FuHaoSanJiao"), new CodeExpression[] { new CodeVariableReferenceExpression("ch"),

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new CodePrimitiveExpression(0) }));
test.Statements.Add(new CodeMethodInvokeExpression(new CodeTypeReferenceExpression("System.Console"), "Read"));
//FuHaoSanJiao
CodeMemberMethod fuHaoSanJiao = new CodeMemberMethod();
fuHaoSanJiao.Name = "FuHaoSanJiao";
fuHaoSanJiao.Parameters.Add(new CodeParameterDeclarationExpression(new CodeTypeReference(typeof(char[])),

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"ch"));
fuHaoSanJiao.Parameters.Add(new CodeParameterDeclarationExpression(new CodeTypeReference(typeof(int)), "start"));
fuHaoSanJiao.Statements.Add(new CodeMethodInvokeExpression(new CodeTypeReferenceExpression("System.Console"),

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"WriteLine", new CodeExpression[] { new CodeObjectCreateExpression(typeof(string), new CodeArgumentReferenceExpression("ch")) }));
fuHaoSanJiao.Statements.Add(new CodeConditionStatement(new CodeBinaryOperatorExpression(

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new CodeArgumentReferenceExpression("start"), CodeBinaryOperatorType.GreaterThanOrEqual,
(new CodeBinaryOperatorExpression(new CodePropertyReferenceExpression(

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new CodeArgumentReferenceExpression("ch"),"Length"),
CodeBinaryOperatorType.Divide ,new CodePrimitiveExpression(2)))),
new CodeMethodReturnStatement()));
CodeBinaryOperatorExpression condition=new CodeBinaryOperatorExpression(

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new CodeVariableReferenceExpression("i"),
CodeBinaryOperatorType.LessThan,
new CodeBinaryOperatorExpression(new CodeBinaryOperatorExpression(new CodePropertyReferenceExpression(new CodeArgumentReferenceExpression("ch"),"Length"),
CodeBinaryOperatorType.Subtract ,new CodeArgumentReferenceExpression("start")), CodeBinaryOperatorType.Subtract,
new CodePrimitiveExpression(1)));//for 条件
CodeConditionStatement iterationBody=new CodeConditionStatement(new CodeBinaryOperatorExpression(
new CodeArrayIndexerExpression(new CodeArgumentReferenceExpression("ch"),

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new CodeVariableReferenceExpression("i")),
CodeBinaryOperatorType.IdentityEquality, new CodeArrayIndexerExpression(

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new CodeArgumentReferenceExpression("ch"),
new CodeBinaryOperatorExpression(new CodeVariableReferenceExpression("i"),

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CodeBinaryOperatorType.Add,new CodePrimitiveExpression(2)))),
new CodeAssignStatement(
new CodeArrayIndexerExpression(new CodeArgumentReferenceExpression("ch"),

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new CodeBinaryOperatorExpression(new CodeVariableReferenceExpression("i"), CodeBinaryOperatorType.Add,

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new CodePrimitiveExpression(1))),
new CodePrimitiveExpression('+')));
iterationBody.FalseStatements.Add(new CodeAssignStatement(
new CodeArrayIndexerExpression(new CodeArgumentReferenceExpression("ch"),

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new CodeBinaryOperatorExpression(new CodeVariableReferenceExpression("i"), CodeBinaryOperatorType.Add,

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new CodePrimitiveExpression(1))),
new CodePrimitiveExpression('-')));
CodeAssignStatement iteerationbody2 = new CodeAssignStatement(new CodeArrayIndexerExpression(

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new CodeArgumentReferenceExpression("ch"), new CodeVariableReferenceExpression("i")),
new CodePrimitiveExpression(' '));
fuHaoSanJiao.Statements.Add(new CodeIterationStatement(new CodeVariableDeclarationStatement(typeof(int),

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"i", new CodeArgumentReferenceExpression("start")), condition,
new CodeAssignStatement(new CodeVariableReferenceExpression("i"),new CodeBinaryOperatorExpression(

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new CodeVariableReferenceExpression("i"), CodeBinaryOperatorType.Add,
new CodePrimitiveExpression(2))), new CodeStatement[] { iterationBody, iteerationbody2 }));
// ch[ch.Length - start - 1] = ' ';
fuHaoSanJiao.Statements.Add(new CodeAssignStatement(
new CodeArrayIndexerExpression(new CodeArgumentReferenceExpression("ch"),

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new CodeBinaryOperatorExpression(new CodeBinaryOperatorExpression(

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new CodePropertyReferenceExpression(new CodeArgumentReferenceExpression("ch"), "Length"),
CodeBinaryOperatorType.Subtract ,new CodeArgumentReferenceExpression("start")),

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CodeBinaryOperatorType.Subtract,
new CodePrimitiveExpression(1))),new CodePrimitiveExpression(' ')));
// FuHaoSanJiao(ch, start + 1);
fuHaoSanJiao.Statements.Add(new CodeMethodInvokeExpression(new CodeThisReferenceExpression(),

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"FuHaoSanJiao",new CodeArgumentReferenceExpression("ch") ,
new CodeBinaryOperatorExpression(new CodeArgumentReferenceExpression("start"),

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CodeBinaryOperatorType.Add, new CodePrimitiveExpression(1))));
CodeTypeDeclaration codeDomDemo2 = new CodeTypeDeclaration("CodeDomDemo2");
codeDomDemo2.Members.Add(test);
codeDomDemo2.Members.Add(fuHaoSanJiao);
codeDomDemo2.Attributes = MemberAttributes.Public;
codeDomDemo2.Comments.Add(new CodeCommentStatement("this code is from CodeDom!"));
//codeDomDemo2.Members.AddRange();
CodeNamespace nspace = new CodeNamespace("CodeDomDemo2");
nspace.Imports.Add(new CodeNamespaceImport("System"));
nspace.Types.Add(codeDomDemo2);
return nspace;
}
}
}

输出代码为：

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namespace CodeDomDemo2
{
using System;
// this code is from CodeDom!
public class CodeDomDemo2
{
public void Test()
{
char[] ch = "+ - + - + + - -".ToCharArray();
this.FuHaoSanJiao(ch, 0);
System.Console.Read();
}
private void FuHaoSanJiao(char[] ch, int start)
{
System.Console.WriteLine(new string(ch));
if ((start
>= (ch.Length / 2)))
{
return;
}
for (int i = start; (i
< ((ch.Length - start)
- 1)); i = (i + 2))
{
if ((ch[i] == ch[(i + 2)]))
{
ch[(i + 1)] = '+';
} else
{
ch[(i + 1)] = '-';
}
ch[i] = ' ';
}
ch[((ch.Length - start)
- 1)] = ' ';
this.FuHaoSanJiao(ch, (start + 1));
}
}
}

代码下载Demo1，Demo2