如何在Asp .Net 3.5 Web应用程序中使用gzip压缩来压缩JavaScript和CSS？

Question

如何在Asp .Net 3.5 Web应用程序中使用gzip压缩来压缩JavaScript和CSS？ Gzip压缩在CSS菜单和验证器脚本中导致错误。

Answer 1

将以下代码添加到Global.asax并将其放入您的根目录。

<%@ Application Language="C#" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.IO.Compression" %>

 <script runat="server">
 void Application_PreRequestHandlerExecute(object sender, EventArgs e)
 {
HttpApplication app = sender as HttpApplication;
string acceptEncoding = app.Request.Headers["Accept-Encoding"];
Stream prevUncompressedStream = app.Response.Filter;

if (!(app.Context.CurrentHandler is Page ||
    app.Context.CurrentHandler.GetType().Name == "SyncSessionlessHandler") ||
    app.Request["HTTP_X_MICROSOFTAJAX"] != null)
    return;

if (acceptEncoding == null || acceptEncoding.Length == 0)
    return;

acceptEncoding = acceptEncoding.ToLower();

if (acceptEncoding.Contains("deflate") || acceptEncoding == "*")
{
    // defalte
    app.Response.Filter = new DeflateStream(prevUncompressedStream,
        CompressionMode.Compress);
    app.Response.AppendHeader("Content-Encoding", "deflate");
} else if (acceptEncoding.Contains("gzip"))
{
    // gzip
    app.Response.Filter = new GZipStream(prevUncompressedStream,
        CompressionMode.Compress);
    app.Response.AppendHeader("Content-Encoding", "gzip");
}
}
</script>

Answer 2

为什么不使用HttpCompression？ 这样一来，您就可以压缩所有静态内容，包括javascript和CSS文件。

HttpCompression IIS 6

HttpCompression IIS 7

Answer 3

（我使用这种技术已经有一段时间了-因此是vb.net代码！）

尽管IIS 6.0不支持压缩，但是大多数浏览器都支持基本的gzip压缩，并且它们通过在每个请求中发送标头来通知服务器此功能。 以下代码段显示了如何使用System.IO.Compression命名空间向输出流添加过滤器，该过滤器在检查和设置正确的标头的同时压缩输出。

 context.Response.Clear()
 context.Response.Buffer = True

 context.Response.AddHeader("content-disposition", String.Format( "attachment;filename={0}", fileName))
 context.Response.ContentEncoding = Encoding.UTF8

 context.Response.Cache.SetCacheability(HttpCacheability.Private)

 'Compress the output as it may be very large
 'When flushing or closing+ending the stream, the compression filter does not have a chance to write the compression footer
 'Therefore, make sure the compression filter stream is closed before flushing
 AddCompression(context)

 context.Response.ContentType = "application/vnd.ms-excel" 'This example was an excel doc

 'Write to response
 context.Response.Write(your-data-here)

 'context.Response.Flush() 'Do not flush if using compression
 'context.Response.Close()
 context.Response.End()

AddCompression方法检查适当的头并将压缩过滤器流添加到输出中：

'Add compression to the response stream
Public Sub AddCompression(ByVal context As HttpContext)

    Dim acceptEncoding As String = context.Request.Headers("Accept-Encoding")
    If acceptEncoding Is Nothing OrElse acceptEncoding.Length = 0 Then Return

    'Convert to lower to check
    acceptEncoding = acceptEncoding.ToLower

    'Gzip or Compress compression
    'Compress compression is quicker and performs better compression so try that first
    If (acceptEncoding.Contains("deflate")) Then

        context.Response.Filter = New DeflateStream(context.Response.Filter, CompressionMode.Compress)
        context.Response.AppendHeader("Content-Encoding", "deflate")

    ElseIf acceptEncoding.Contains("gzip") Then

        context.Response.Filter = New GZipStream(context.Response.Filter, CompressionMode.Compress)
        context.Response.AppendHeader("Content-Encoding", "gzip")

    End If

End Sub

Answer 4

下载gzip压缩示例代码，并将其添加到您的Global.asax文件中。