• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 980
  • Last Modified:

Prevent Caching of Web Pages - How to Test?

My ASP.NET 1.1 application has a problem with some users' browsers caching pages that postback to them selves. I want to implement the solution(s) posted in this Question: http://www.experts-exchange.com/Programming/Languages/.NET/ASP.NET/Q_21935367.html.

Is there any way to test and prove that the solution(s) posted will correct my problem in a Test Environment without just putting it into Production and waiting for customer feedback? I found I can "reproduce" the problem by setting IE to Never check for new versions but, so far, that seems to completely override the suggested solutions. Thank you for your assistance.

Also, when I tried adding the following:

  <meta http-equiv="Expires" CONTENT="0">
  <meta http-equiv="Cache-Control" CONTENT="no-cache">
  <meta http-equiv="Pragma" CONTENT="no-cache">

they didn't appear in my html when I viewed the source. Is that expected with these meta tags?
  • 2
  • 2
  • 2
2 Solutions
I use this code in a production environment to prevent cacheing. It will for a page refresh everytime.
protected void Page_Load(object sender, EventArgs e)
System.Web.HttpContext.Current.Response.Cache.SetNoServerCaching();			System.Web.HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.NoCache);

Open in new window

The meta tags should appear in source when you view it. if you use strickdd's solution you will not need to add any other meta tags to your html. the server will take care of all caching issues.
since your product is ready for production, I would use the code provided by strickdd and in a module instead of writing it to the page load of every page
If you have a masterpage, you can just include it in the page load of the mastpage if that works better.
Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

ZekeLAAuthor Commented:
Thank you all for the suggestions. I ran into a problem with one page which returned a PDF file to the user using Content-Disposition [attachment; filename="MyFileName"]  but I just needed to call Response.ClearHeaders() firs.

However, I'm still not sure I've fixed the problem. I added the following code to Application_BeginRequest:

         Response.Cache.SetCacheability(HttpCacheability.NoCache)    ' Same as next three options:
         'Response.Expires = -1                                      '  - Expire Immediately
         'Response.AddHeader("pragma", "no-cache")
         'Response.CacheControl = "no-cache"                         '  - Set HTTP/1.1 protocol so proxy servers or
         '                                                           '    other cache mechanisms will not cache pages
         Response.ExpiresAbsolute = DateTime.Now.AddDays(-2)         ' Subtract two days instead of one in case of Int'l Date Line
         Response.Cache.SetRevalidation(HttpCacheRevalidation.AllCaches)   ' Set HTTP/1.1 directive

When I look at the rendered page output using my browser, however, I don't see any additional meta tags. Is that correct? Do I need to look at IIS configuration?

Lastly, none of the suggestions answer the primary questions: How can I test and / or validate that the changes are working? Everywhere on the web, you can find similar suggestions. But I've yet to see how to actually test this without putting it into production and hoping that it fixes any customer issues. Can anyone answer that part of the question?
If you write to the Response Object, the tags will not be shown in the html
to test the cache, just drop a label on any of the pages you have and testing it using one of the DateTime.Now.ToString(); then refresh the page, if its cached the label value will not change "Keeps the initial DateTime value"

ZekeLAAuthor Commented:
I've implemented most of strickdd's solution and haven't had negative user feedback yet.
Sammy1971 answered one of my nagging questions.
I didn't really get an answer on how to test the caching. In the real world, this is dependent on the user's ISP and other servers between them and my web server so I'll just have to rely on user feedback if the problem still continues.
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Get your problem seen by more experts

Be seen. Boost your question’s priority for more expert views and faster solutions

  • 2
  • 2
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now