自定义Response.Filter得到输出流stream生成动态页面的静态内容(磁盘缓存)如下的代码我们可以看出我们以 request.RawUrl 为缓存基础因为它可以包含任意的QueryString变量然后我们用MD5加密RawUrl 得到服务器本地文件名的变量再实例化一个FileInfo操作该文件如果文件最后一次生成时间小于7天我们就使用.Net2.0新增的TransmitFile方法将存储文件的静态内容发送到浏览器。如果文件不存在我们就操作 response.Filter 得到的 Stream 传递给 CommonFilter 类并利用FileStream写入动态页面的内容到静态文件中。namespace ASPNET_CL.Code.HttpModules { public class CommonModule : IHttpModule { public void Init( HttpApplication application ) { application.BeginRequest Application_BeginRequest; } private void Application_BeginRequest( object sender, EventArgs e ) { var context HttpContext.Current; var request context.Request; var url request.RawUrl; var response context.Response; var path GetPath( url ); var file new FileInfo( path ); if ( DateTime.Now.Subtract( file.LastWriteTime ).TotalDays 7 ) { response.TransmitFile( path ); response.End(); return; } try { var stream file.OpenWrite(); response.Filter new CommonFilter( response.Filter, stream ); } catch ( Exception ) { //Log.Insert(); } } public void Dispose() { } private static string GetPath( string url ) { var hash Hash( url ); string fold HttpContext.Current.Server.MapPath( ~/Temp/ ); return string.Concat( fold, hash ); } private static string Hash( string url ) { url url.ToUpperInvariant(); var md5 new System.Security.Cryptography.MD5CryptoServiceProvider(); var bs md5.ComputeHash( Encoding.ASCII.GetBytes( url ) ); var s new StringBuilder(); foreach ( var b in bs ) { s.Append( b.ToString( x2 ).ToLower() ); } return s.ToString(); } } }二、页面GZIP压缩对页面GZIP压缩几乎是每篇讲解高性能WEB程序的几大做法之一因为使用GZIP压缩可以降低服务器发送的字节数能让客户感觉到网页的速度更快也减少了对带宽的使用情况。当然这里也存在客户端的浏览器是否支持它。因此我们要做的是如果客户端支持GZIP我们就发送GZIP压缩过的内容如果不支持我们直接发送静态文件的内容。幸运的是现代浏览器IE6.7.8.0火狐等都支持GZIP。为了实现这个功能我们需要改写上面的 Application_BeginRequest 事件private void Application_BeginRequest( object sender, EventArgs e ) { var context HttpContext.Current; var request context.Request; var url request.RawUrl; var response context.Response; var path GetPath( url ); var file new FileInfo( path ); // 使用页面压缩 ResponseCompressionType compressionType this.GetCompressionMode( request ); if ( compressionType ! ResponseCompressionType.None ) { response.AppendHeader( Content-Encoding, compressionType.ToString().ToLower() ); if ( compressionType ResponseCompressionType.GZip ) { response.Filter new GZipStream( response.Filter, CompressionMode.Compress ); } else { response.Filter new DeflateStream( response.Filter, CompressionMode.Compress ); } } if ( DateTime.Now.Subtract( file.LastWriteTime ).TotalMinutes 5 ) { response.TransmitFile( path ); response.End(); return; } try { var stream file.OpenWrite(); response.Filter new CommonFilter( response.Filter, stream ); } catch ( Exception ) { //Log.Insert(); } } private ResponseCompressionType GetCompressionMode( HttpRequest request ) { string acceptEncoding request.Headers[ Accept-Encoding ]; if ( string.IsNullOrEmpty( acceptEncoding ) ) return ResponseCompressionType.None; acceptEncoding acceptEncoding.ToUpperInvariant(); if ( acceptEncoding.Contains( GZIP ) ) return ResponseCompressionType.GZip; else if ( acceptEncoding.Contains( DEFLATE ) ) return ResponseCompressionType.Deflate; else return ResponseCompressionType.None; } private enum ResponseCompressionType { None, GZip, Deflate }三、OutputCache 编程方式输出页面缓存ASP.NET内置的 OutputCache 缓存可以将内容缓存在三个地方Web服务器、代理服务器和浏览器。当用户访问一个被设置为 OutputCache的页面时ASP.NET在MSIL之后先将结果写入output cache缓存然后在发送到浏览器当用户访问同一路径的页面时ASP.NET将直接发送被Cache的内容而不经过.aspx编译以及执行MSIL的过程所以虽然程序的本身效率没有提升但是页面载入速度却得到了提升。为了实现这个功能我们继续改写上面的 Application_BeginRequest 事件我们在 TransmitFile 后将这个路径的页面以OutputCache编程的方式缓存起来private void Application_BeginRequest( object sender, EventArgs e ) { //............. if ( DateTime.Now.Subtract( file.LastWriteTime ).TotalMinutes 5 ) { response.TransmitFile( path ); // 添加 OutputCache 缓存头并缓存在客户端 response.Cache.SetExpires( DateTime.Now.AddMinutes( 5 ) ); response.Cache.SetCacheability( HttpCacheability.Public ); response.End(); return; } //............ }四、实现CommonFilter类过滤ViewState、过滤NamingContainer、空白字符串以及生成磁盘的缓存文件我们传入response.Filter的Stream对象给CommonFilter类首先我们用先Stream的Write方法实现生成磁盘的缓存文件代码如下在这些代码中只有初始化构造函数Write方法Close方式是有用的其中FileStream字段是生成静态文件的操作对象namespace ASPNET_CL.Code.HttpModules { public class CommonFilter : Stream { private readonly Stream _responseStream; private readonly FileStream _cacheStream; public override bool CanRead { get { return false; } } public override bool CanSeek { get { return false; } } public override bool CanWrite { get { return _responseStream.CanWrite; } } public override long Length { get { throw new NotSupportedException(); } } public override long Position { get { throw new NotSupportedException(); } set { throw new NotSupportedException(); } } public CommonFilter( Stream responseStream, FileStream stream ) { _responseStream responseStream; _cacheStream stream; } public override long Seek( long offset, SeekOrigin origin ) { throw new NotSupportedException(); } public override void SetLength( long length ) { throw new NotSupportedException(); } public override int Read( byte[] buffer, int offset, int count ) { throw new NotSupportedException(); } public override void Flush() { _responseStream.Flush(); _cacheStream.Flush(); } public override void Write( byte[] buffer, int off