代码生成技术
目标
通过xml文件的配置生成C#代码.
示例
1. 编辑xml文件
<?xml version="1.0" encoding="utf-8" ?>
<dataentitytypes>
<dataentitytype domain="database">
<name>School</name>
<properties>
<simpleproperties>
<simpleproperty name="Id" dbtype="string">
<description>id</description>
</simpleproperty>
<simpleproperty name="Name" dbtype="string">
<description>name</description>
</simpleproperty>
</simpleproperties>
<collectionproperties>
<collectionproperty name="Classes">
<itemdataentitytypename>Class</itemdataentitytypename>
</collectionproperty>
</collectionproperties>
</properties>
</dataentitytype>
<dataentitytype>
<name>Class</name>
<properties>
<simpleproperties>
<simpleproperty name="Id" dbtype="string">
<description>id</description>
</simpleproperty>
<simpleproperty name="Name" dbtype="string">
<description>name</description>
</simpleproperty>
<simpleproperty name="Member" dbtype="int">
<description>member</description>
</simpleproperty>
</simpleproperties>
</properties>
</dataentitytype>
</dataentitytypes>
2. 编辑xslt文件
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl"
>
<xsl:output method="text" indent="yes"/>
<xsl:template match="/">
/*
*auto-generated
*/
using System;
using System.Collections.Generic;
namespace DataEntity
{
<xsl:for-each select="dataentitytypes/dataentitytype">
public sealed class <xsl:call-template name="classname"></xsl:call-template>
{
<xsl:call-template name="simpleproperties"></xsl:call-template>
<xsl:call-template name="collectionproperties"></xsl:call-template>
}
</xsl:for-each>
}
</xsl:template>
<xsl:template name="classname">
<xsl:value-of select="name"/>
</xsl:template>
<xsl:template name="simpleproperties">
<xsl:for-each select="properties/simpleproperties/simpleproperty">
public <xsl:value-of select="@dbtype"/><xsl:text> </xsl:text><xsl:value-of select="@name"/>
{
get;
set;
}
</xsl:for-each>
</xsl:template>
<xsl:template name="collectionproperties">
<xsl:for-each select="properties/collectionproperties/collectionproperty">
public IList <<xsl:value-of select="itemdataentitytypename"/>><xsl:text> </xsl:text><xsl:value-of select="@name"/>
{
get;
set;
}
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
小技巧:Xslt文件编写之后是可以在VS中调试和显示输出的,点击XSLT文件,然后VS菜单栏会多出一个XML的菜单,选择即可!
3. 编写转换类
using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;
using System.Xml.Xsl;
namespace XML
{
public class DataEntityGenerator
{
public static void Compile(string stylesheetUri,string inputUri,string outputFile)
{
XslCompiledTransform transform = new XslCompiledTransform(true);
transform.Load(stylesheetUri);
transform.Transform(inputUri, outputFile);
}
}
}
4. 运行结果
/*
*auto-generated
*/
using System;
using System.Collections.Generic;
namespace DataEntity
{
public sealed class School
{
public string Id
{
get;
set;
}
public string Name
{
get;
set;
}
public IList<Class> Classes
{
get;
set;
}
}
public sealed class Class
{
public string Id
{
get;
set;
}
public string Name
{
get;
set;
}
public int Member
{
get;
set;
}
}
}
小结
本文仅仅是介绍一种简单的代码生成技术.如果按照此方法设计代码生成器,最好对XML,XPath,XSD,XSL,XSLT以及IO流有一定的了解.所有的XML相关的文档的知识都可以在http://www.w3school.com.cn查到,与XML相关的类库主要分布在System.Xml程序集中(对xml可以使用LinqToXml技术),除此之外,XML相关的类与IO中的许多流也有密切联系.
作者:zhoulq