/// <summary> 
/// CompressWhitespaceFilter 
/// </summary> 
public class CompressWhitespaceFilter : Stream 
{ 
private GZipStream _contentGZipStream; 
private DeflateStream _content_DeflateStream; 
private Stream _contentStream; 
private CompressOptions _compressOptions; 
/// <summary> 
/// Initializes a new instance of the <see cref="CompressWhitespaceFilter"/> class. 
/// </summary> 
/// <param name="contentStream">The content stream.</param> 
/// <param name="compressOptions">The compress options.</param> 
public CompressWhitespaceFilter(Stream contentStream, CompressOptions compressOptions) 
{ 
if (compressOptions == CompressOptions.GZip) 
{ 
this._contentGZipStream = new GZipStream(contentStream, CompressionMode.Compress); 
this._contentStream = this._contentGZipStream; 
} 
else if (compressOptions == CompressOptions.Deflate) 
{ 
this._content_DeflateStream = new DeflateStream(contentStream,CompressionMode.Compress); 
this._contentStream = this._content_DeflateStream; 
} 
else 
{ 
this._contentStream = contentStream; 
} 
this._compressOptions = compressOptions; 
} 
public override bool CanRead 
{ 
get { return this._contentStream.CanRead; } 
} 
public override bool CanSeek 
{ 
get { return this._contentStream.CanSeek; } 
} 
public override bool CanWrite 
{ 
get { return this._contentStream.CanWrite; } 
} 
public override void Flush() 
{ 
this._contentStream.Flush(); 
} 
public override long Length 
{ 
get { return this._contentStream.Length; } 
} 
public override long Position 
{ 
get 
{ 
return this._contentStream.Position; 
} 
set 
{ 
this._contentStream.Position = value; 
} 
} 
public override int Read(byte[] buffer, int offset, int count) 
{ 
return this._contentStream.Read(buffer, offset, count); 
} 
public override long Seek(long offset, SeekOrigin origin) 
{ 
return this._contentStream.Seek(offset, origin); 
} 
public override void SetLength(long value) 
{ 
this._contentStream.SetLength(value); 
} 
public override void Write(byte[] buffer, int offset, int count) 
{ 
byte[] data = new byte[count + 1]; 
Buffer.BlockCopy(buffer, offset, data, 0, count); 
string strtext = System.Text.Encoding.UTF8.GetString(data); 
strtext = Regex.Replace(strtext, "^\\s*", string.Empty, RegexOptions.Compiled | RegexOptions.Multiline); 
strtext = Regex.Replace(strtext, "\\r\\n", string.Empty, RegexOptions.Compiled | RegexOptions.Multiline); 
strtext = Regex.Replace(strtext, "<!--*.*?-->", string.Empty, RegexOptions.Compiled | RegexOptions.Multiline); 
byte[] outdata = System.Text.Encoding.UTF8.GetBytes(strtext); 
this._contentStream.Write(outdata, 0, outdata.GetLength(0)); 
} 
} 
/// <summary> 
/// CompressOptions 
/// </summary> 
/// <seealso cref="http://en.wikipedia.org/wiki/Zcat#gunzip_and_zcat"/> 
/// <seealso cref="http://en.wikipedia.org/wiki/DEFLATE"/> 
public enum CompressOptions 
{ 
GZip, 
Deflate, 
None 
} 

上面的代码使用正则表达式替换字符串,你可以修改那些正则表达式来满足你的需求. 我们同时使用了GZipStream与DeflateStream实现了压缩. 好的,接下来与
HttpModule结合:
 代码如下:

/// <summary> 
/// CompressWhitespaceModule 
/// </summary> 
public class CompressWhitespaceModule : IHttpModule 
{ 
#region IHttpModule Members 
/// <summary> 
/// Disposes of the resources (other than memory) used by the module that implements <see cref="T:System.Web.IHttpModule"/>. 
/// </summary> 
public void Dispose() 
{ 
// Nothing to dispose; 
} 
/// <summary> 
/// Initializes a module and prepares it to handle requests. 
/// </summary> 
/// <param name="context">An <see cref="T:System.Web.HttpApplication"/> that provides access to the methods, properties, and events common to all application objects within an ASP.NET application</param> 
public void Init(HttpApplication context) 
{ 
context.BeginRequest += new EventHandler(context_BeginRequest); 
} 
/// <summary> 
/// Handles the BeginRequest event of the context control. 
/// </summary> 
/// <param name="sender">The source of the event.</param> 
/// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param> 
void context_BeginRequest(object sender, EventArgs e) 
{ 
HttpApplication app = sender as HttpApplication; 
if (app.Request.RawUrl.Contains(".aspx")) 
{ 
HttpContext context = app.Context; 
HttpRequest request = context.Request; 
string acceptEncoding = request.Headers["Accept-Encoding"]; 
HttpResponse response = context.Response; 
if (!string.IsNullOrEmpty(acceptEncoding)) 
{ 
acceptEncoding = acceptEncoding.ToUpperInvariant(); 
if (acceptEncoding.Contains("GZIP")) 
{ 
response.Filter = new CompressWhitespaceFilter(context.Response.Filter, CompressOptions.GZip); 
response.AppendHeader("Content-encoding", "gzip"); 
} 
else if (acceptEncoding.Contains("DEFLATE")) 
{ 
response.Filter = new CompressWhitespaceFilter(context.Response.Filter, CompressOptions.Deflate); 
response.AppendHeader("Content-encoding", "deflate"); 
} 
} 
response.Cache.VaryByHeaders["Accept-Encoding"] = true; 
} 
} 
#endregion 
} 
 
HttpApplication.BeginRequest 事件是 在 ASP.NET 响应请求时作为 HTTP 执行管线链中的第一个事件发生。 
在WEB.CONFIG中你还需要配置: 
 代码如下:

<httpModules> 
<add name="CompressWhitespaceModule" type="MyWeb.CompressWhitespaceModule" /> 
</httpModules> 
 

我们来看一下效果,下面没有使用时, 4.8KB
 
接着看,处理过后的效果,Cotent-Encoding: gzip,  filezie: 1.6KB
 
很简单,你可以按需求来增加更多的功能. 希望对您开发有帮助.
作者：Petter Liu 
 
 




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