FAQ - Frequently Asked Questions

Re: How to prevent browser and proxy caching of web pages

Evervision — Thu, 18 Oct 2007 19:33:13 GMT

I found that "ClearHeaders" when called at the wrong time prevented people from logging in. So I removed it for mine. I also found that repeated calls to add "Cache-Control" overwrote the previous calls on IIS 6.0/2k3 Server/ .Net 2.0. So I put them all in the same one. I also added the "max-age=0" to "Cache-Control" for Firefox.

        Response.AppendHeader("Cache-Control", "no-cache; private; no-store; must-revalidate; max-stale=0; post-check=0; pre-check=0; max-age=0"); // HTTP 1.1
        Response.AppendHeader("Pragma", "no-cache"); // HTTP 1.1
        Response.AppendHeader("Keep-Alive", "timeout=3, max=993"); // HTTP 1.1
        Response.AppendHeader("Expires", "Mon, 26 Jul 1997 05:00:00 GMT"); // HTTP 1.1

Re: How to prevent browser and proxy caching of web pages

ashwani2kumar — Wed, 10 Oct 2007 09:43:03 GMT

hello use this

Response.ClearHeaders();
            Response.AppendHeader("Cache-Control", "no-cache"); //HTTP 1.1
            Response.AppendHeader("Cache-Control", "private"); // HTTP 1.1
            Response.AppendHeader("Cache-Control", "no-store"); // HTTP 1.1
            Response.AppendHeader("Cache-Control", "must-revalidate"); // HTTP 1.1
            Response.AppendHeader("Cache-Control", "max-stale=0"); // HTTP 1.1
            Response.AppendHeader("Cache-Control", "post-check=0"); // HTTP 1.1
            Response.AppendHeader("Cache-Control", "pre-check=0"); // HTTP 1.1
            Response.AppendHeader("Pragma", "no-cache"); // HTTP 1.1
            Response.AppendHeader("Keep-Alive", "timeout=3, max=993"); // HTTP 1.1
            Response.AppendHeader("Expires", "Mon, 26 Jul 1997 05:00:00 GMT"); // HTTP 1.1

Ashwani

Re: How to prevent browser and proxy caching of web pages

ilovebbs — Tue, 09 Oct 2007 13:25:48 GMT

LudovicoVan:

Maybe keep in mind that outputs an HTTP/1.1 compliant Cache-Control header, not the deprecated HTTP/1.0 Pragma: NoCache. Also, sending HTTP headers as META tags as you show above is furtherly deprecated and known to be unreliable, so that's maybe where your original problems came from

i agree this talk.

Re: How to prevent browser and proxy caching of web pages

nisarkhan — Tue, 11 Sep 2007 14:19:51 GMT

trust me guys i have tried all the technique you can think of

page_header:

<script language="JavaScript" type="text/javascript">
window.history.forward(1);
</script>

but still i able to click on back button, i'm using IE7

Re: How to prevent browser and proxy caching of web pages

Sonali Das — Tue, 11 Sep 2007 05:45:23 GMT

To make Back button disabled , you can use the following line of code in the Web page(.aspx):

I think it might help.

Re: How to prevent browser and proxy caching of web pages

shaurya — Mon, 10 Sep 2007 12:35:55 GMT

Hi NisarKhan,

If you want the user to stay on the same page when pressing back button in internet explorer. Just put the folloing javascript in the page from where you are coming to this page(where you don't want to user go back through back button).

Hope it works for you

Shaurya Tomer

Re: How to prevent browser and proxy caching of web pages

nisarkhan — Fri, 07 Sep 2007 21:53:06 GMT

RalphCEO:

Set it at the IIS level.

Open IIS and right click on your Web Site or Virtual Directory and click Properties. Select the Http Headers tab. In the top of the dialogue window is a check box, "Enable Content Expiration" Select it. Then select the option to "Expire Immediately"

That should do it.

does that mean that, user wont be able to click on back button in normal browsing pages? i mean to say the, the expire should happen only when the time expired? by changing the setting on IIS server does that mean, user wont be able to click back button and browse different pages?

thoughts?

Re: How to prevent browser and proxy caching of web pages

RalphCEO — Fri, 07 Sep 2007 20:59:14 GMT

Set it at the IIS level.

Open IIS and right click on your Web Site or Virtual Directory and click Properties. Select the Http Headers tab. In the top of the dialogue window is a check box, "Enable Content Expiration" Select it. Then select the option to "Expire Immediately"

That should do it.

Re: How to prevent browser and proxy caching of web pages

anilakhwaja — Mon, 16 Jul 2007 06:14:49 GMT

We have done this

protected override void OnLoad(EventArgs e) { Response.Cache.SetNoStore(); Response.Cache.SetCacheability(HttpCacheability.NoCache); Response.Cache.SetExpires(DateTime.Now); base.OnLoad(e); }But this solves the problem only on LAN.For fixed IP, caching problem persists.

so ne other option to resolve da problem ...

Re: How to prevent browser and proxy caching of web pages

sdgough — Fri, 13 Jul 2007 14:36:17 GMT

One option would be to version your js files? This article, although primarily about PowerShell, talks about this approach (sample code available on Code Project) -- http://msmvps.com/blogs/omar/archive/2006/12/15/automate-website-deployment-using-powershell.aspx

Another option would be to include your js files as embedded resources. This is what we do (actually we compress and obfuscate them too via Aptana). Now I am not 100% certain, but I believe a new version of your js files would create a new embedded resource string (<WebResource.axd?d=XXXX) and therefore prevent caching of an older version.

Re: How to prevent browser and proxy caching of web pages

anilakhwaja — Fri, 13 Jul 2007 11:41:55 GMT

Can u plz help me in the scenerio which is some what the same .. .as its addressing here

sccenario:

we have a proxy server which is assigned by a fixed ip and user access it through proxy ...

we have deployed our application over there, which is built in ASP.NET 2.0 and we have also used seperate javascript files (*.js) and proxy server as usual caches the page and javascript files

when ever we have some changes we deploy our application again at the proxy server

but when we run the application it uses the same cached javascript files and dont use the new one which we have deployed

can you help me in this regard that what should i do ???

Re: How to prevent browser and proxy caching of web pages

nisarkhan — Fri, 15 Jun 2007 15:56:53 GMT

i have been looking for the solutions from pretty long time and after reading this thread i'm still having no luck

i followed everything you guys have talked here but nothing works

is anybody can help please?

i have a windows authentication mode using asp.net 2 C#

if a user clicks on back button i want the user to stay on the same page or expire the back button or disable the back button but something that when user clicks back button i dont want the user to be able to go to previous page

also i have open a new thread if you please wanna look at it?

http://forums.asp.net/t/1120854.aspx

thanks

Re: How to prevent browser and proxy caching of web pages

buntybunty — Tue, 27 Feb 2007 09:49:20 GMT

I have updated the code, the changes were not persisting the way i desired. New code below:

            Response.ClearHeaders();
            Response.AppendHeader("Cache-Control", "no-cache"); //HTTP 1.1
            Response.AppendHeader("Cache-Control", "private"); // HTTP 1.1
            Response.AppendHeader("Cache-Control", "no-store"); // HTTP 1.1
            Response.AppendHeader("Cache-Control", "must-revalidate"); // HTTP 1.1
            Response.AppendHeader("Cache-Control", "max-stale=0"); // HTTP 1.1 
            Response.AppendHeader("Cache-Control", "post-check=0"); // HTTP 1.1 
            Response.AppendHeader("Cache-Control", "pre-check=0"); // HTTP 1.1 
            Response.AppendHeader("Pragma", "no-cache"); // HTTP 1.1 
            Response.AppendHeader("Keep-Alive", "timeout=3, max=993"); // HTTP 1.1 
            Response.AppendHeader("Expires", "Mon, 26 Jul 1997 05:00:00 GMT"); // HTTP 1.1

Re: How to prevent browser and proxy caching of web pages

buntybunty — Tue, 27 Feb 2007 09:34:55 GMT

How to prevent browser and proxy caching of web pages what is the mean of this sentances?

Re: How to prevent browser and proxy caching of web pages

cozyshri23 — Tue, 27 Feb 2007 07:59:42 GMT

The above lines dont seem to work for fireFox 2.0 .

I need to clear the cache coz when I do a browser back, there is data on my textbox.