【转载】Yui.Compressor高性能ASP.NET开发：自动压缩CSS、JS

在开发中编写的js、css发布的时候，往往需要进行压缩，以减少文件大小，减轻服务器的负担。这就得每次发版本的时候，对js、js进行压缩，然后再发布。有没有什么办法，让代码到了服务器上边，它自己进行压缩呢？

有两种办法：

第一种，在css、js请求到来的时候读取一下相对应的文件，进行压缩后返回。此方法可以通过在Global.asax的Application_BeginRequest的事件中，进行处理，也可以在web.config中注册一个httpHandler进行处理。

第二种是在程序启动的时候，对全部css以及js进行压缩，压缩之后，每次访问都使用压缩后的文件即可。这种办法可以将js全部压缩到一个文件夹里边，不过需要注意一下文件的顺序。

压缩使用的是雅虎的压缩组件: Yahoo.Yui.Compressor.dll

由于第一种办法没能实现js压缩到一个文件，所以这里采用的是第二种方案。

压缩方法比较简单，首先引用Yahoo.Yui.Compressor.dll和EcmaScript.NET.modified.dll

压缩js

//文件内容

string strContent = File.ReadAllText(jsPath, Encoding.UTF8);

//初始化

var js = new JavaScriptCompressor(strContent, false, Encoding.UTF8, System.Globalization.CultureInfo.CurrentCulture);

//压缩该js

strContent = js.Compress();

File.WriteAllText(jsPath, strContent, Encoding.UTF8);

压缩css

string strContent = File.ReadAllText(cssPath, Encoding.UTF8)

//进行压缩

strContent = CssCompressor.Compress

(strContent);

File.WriteAllText(cssPath, strContent, Encoding.UTF8);

还有另外一一种办法不用自己写代码，每次网站发布的时候自动压缩指定的js和css文件：
1）在项目中新建“MSBuild” 文件夹，把yahoo压缩组件的两个dll放进去
2）在“文件夹”内新建"MSBuildCompressor.xml"文件:

<?xml version="1.0" encoding="utf-8" ?>

<Project xmlns="http://schemas.microsoft.com/developer/MsBuild/2003">

  <UsingTask

  TaskName="CompressorTask"

  AssemblyFile="Yahoo.Yui.Compressor.dll" />

  <!-- The .NET 2.0 version of the task .. and yes .. that's Model.Net20 folder listed twice .. i know i know...

<UsingTask

TaskName="CompressorTask"

        AssemblyFile="..\..\Projects\Yahoo.Yui.Compressor\Model.Net20\Model.Net20\bin\Debug\Yahoo.Yui.Compressor.NET20.dll" />

    -->

  <!-- Define the output locations. These can be set via the msbuild command line using

         /p:CssOutputFile=$(TargetDir)../whatever...

         /p:JavaScriptOutputFile=$(TargetDir)../whatever...

         If they are not supplied or are empty, then we the value whatever is supplied, below.

    -->

  <PropertyGroup>

    <CssOutputFile Condition=" '$(CssOutputFile)'=='' ">

      SylesSheetFinal.css

    </CssOutputFile>

    <JavaScriptOutputFile Condition=" '$(JavaScriptOutputFile)'=='' ">

      JavaScriptFinal.css

    </JavaScriptOutputFile>

  </PropertyGroup>

  <Target Name="MyTaskTarget">

    <!--

ItemGroup\CssFiles or ItemGroup\JavaScriptFiles: add zero to many files you wish to include in this compression task.

                                                             Don't forget, you can use the wildcard (eg. *.css, *.js) if you feel up to it.

                                                             Finally, at least one item is required - either a css file or a js file.

CssFiles/JavaScriptFiles data format: Please do not touch this.

DeleteCssFiles: [Optional] True | Yes | Yeah | Yep | True | FoSho | FoSho. Default is False. Anything else is False. (eg. blah = false, xxxx111 = false, etc)

CssCompressionType: YuiStockCompression | MichaelAshsRegexEnhancements | HaveMyCakeAndEatIt or BestOfBothWorlds or Hybrid; Default is YuiStockCompression.

ObfuscateJavaScript: [Optional] refer to DeleteCssFiles, above.

PreserveAllSemicolons: [Optional] refer to DeleteCssFiles, above.

DisableOptimizations: [Optional] refer to DeleteCssFiles, above.

EncodingType: [Optional] ASCII, BigEndianUnicode, Unicode, UTF32, UTF7, UTF8, Default. Default is 'Default'.

DeleteJavaScriptFiles: [Optional] refer to DeleteCssFiles, above.

LineBreakPosition: [Optional] the position where a line feed is appened when the next semicolon is reached. Default is -1 (never add a line break).
(zero) means add a line break after every semicolon. (This might help with debugging troublesome files).         

LoggingType: None | ALittleBit | HardcoreBringItOn;  Hardcore also lists javascript verbose warnings, if there are any (and there usually is :P ).

ThreadCulture: [Optional] the culture you want the thread to run under. Default is 'en-gb'.

IsEvalIgnored: [Optional] compress any functions that contain 'eval'. Default is False, which means a function that contains

                           'eval' will NOT be compressed. It's deemed risky to compress a function containing 'eval'. That said,

if the usages are deemed safe this check can be disabled by setting this value to True.

        -->

    <ItemGroup>

      <!-- Single files, listed in order of dependency 

      <CssFiles Include="../StylesheetSample1.css"/>

      <CssFiles Include="../StylesheetSample2.css"/>

      <CssFiles Include="../StylesheetSample3.css"/>

      <CssFiles Include="../StylesheetSample4.css"/>-->

      <JavaScriptFiles Include="../myjs/sample_1.js"/>

      <!-- All the files. They will be handled (I assume) in alphabetically. -->

      <!--<CssFiles Include="*.css" />

<JavaScriptFiles Include="*.js" />

            -->

    </ItemGroup>

    <CompressorTask

    CssFiles="@(CssFiles)"

    DeleteCssFiles="false"

    CssOutputFile="$(CssOutputFile)"

    CssCompressionType="YuiStockCompression"

    JavaScriptFiles="@(JavaScriptFiles)"

    ObfuscateJavaScript="False"

    PreserveAllSemicolons="False"

    DisableOptimizations="Nope"

    EncodingType="utf-8"            

    DeleteJavaScriptFiles="false"

    LineBreakPosition="-1"

    JavaScriptOutputFile="$(JavaScriptOutputFile)"

    LoggingType="ALittleBit"

    ThreadCulture="en-au"

    IsEvalIgnored="false"

    />

    <!--

    CssFiles="@(CssFiles)"

    DeleteCssFiles="false"

    CssOutputFile="$(CssOutputFile)"

    CssCompressionType="YuiStockCompression"

    JavaScriptFiles="@(JavaScriptFiles)"

    ObfuscateJavaScript="False"                   //是否模糊处理js文件，True：会将js中的变量为“a,b,c”单个字符的变量

    PreserveAllSemicolons="False"

    DisableOptimizations="Nope"

    EncodingType="utf-8"                          //如果js或者css包含有中文，则必须使用utf-8编码，否则会乱码

    DeleteJavaScriptFiles="false"

    LineBreakPosition="-1"

    JavaScriptOutputFile="$(JavaScriptOutputFile)"

    LoggingType="ALittleBit"

    ThreadCulture="en-au"

    IsEvalIgnored="false"

    -->

  </Target>

</Project>

3）选择网站属性，切换到“生成事件”标签，，在“”输入以下命令：
$(MSBuildBinPath)\msbuild.exe "$(ProjectDir)MSBuild\MSBuildCompressor.xml" /p:CssOutputFile="../miniFile/Sieena.min.css" /p:JavaScriptOutputFile="../miniFile/Sieena.min.js"

这样，每次编译网站的时候就会自动压缩指定的js和css文件了

实例下载

官方地址：

http://yuicompressor.codeplex.com/wikipage?title=Sample%20MSBuild.xml%20File&ProjectName=yuicompressor