caching trouble: dynamic css files
I have some css files that need to be generated dynamically (why is complicated, but it's necessary). The easy solution is to change the files to aspx files, and use <%= %> tags as needed to inject the values I want.
This works fine, until we get to caching. It seems that the browser and server refuse to cache the file. I've tried manipulating the various http cache headers, but the browser always re-gets the file on each page load. The server always responds with HTTP 200 (and the correct content), rather than with a 304 (file unchanged).
How can I convince the browser and the server to cache these dynamic css files?
Example consuming file:
<html> <head> <link href="/style.aspx" type="text/css" rel="stylesheet"/>...
Exa开发者_StackOverflowmple style sheet, with cache header manipulation (omitting dynamic part of file):
<%@ Page Language="C#" ContentType="text/css" EnableSessionState="False" %><%Response.Cache.SetLastModified(new DateTime(2009, 11, 18, 10, 1, 0));Response.Cache.SetMaxAge(TimeSpan.FromDays(30));Response.Cache.SetETag("4ffff353ff67ff1:0");%>...css here...
The request headers to the server includes the following:
If-Modified-Since Wed, 18 Nov 2009 18:01:00 GMTCache-Control max-age=0
And the related server response headers are:
Cache-Control private, max-age=2592000Last-Modified Wed, 18 Nov 2009 18:01:00 GMTDate Wed, 18 Nov 2009 19:36:07 GMT
Any ideas?
generate dynamic file and set the content type to the same cotent type of css and then it will treated as css no need to send it as aspx even if you are generating it dynamically
How about caching the .aspx page that is acting as a css file using something like this:
<%@ OutputCache Duration="60" Location="Client" VaryByParam="None" %>
How to cache in ASP.NET by using Visual C# .NET
Have you tried Response.SetExpires()? This is a little simpler than setting the mod date and max age - maybe your browser will like it better.
edit: Didn't realize this was such an old question, hopefully this still helps someone out there.
Can you pass a bogus, randomly generated querystring to force the recache?
For example:
<link href="<%=sStyleSheet%>" type="text/css" rel="stylesheet" />
and then something like this in your codebehind
Random random = new Random();
int num = random.Next(100000);
string sStyleSheet = "/style.aspx?q=" + num.ToString();
加载中,请稍侯......
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