Question

I assumed that sending a page out with an expiry (a la)…

    Response.Cache.SetExpires(System.DateTime.Now.AddSeconds(5));
    Response.Cache.SetCacheability(HttpCacheability.Public);
    Response.Cache.SetValidUntilExpires(true);

…would mean that if the user hit the back button they would see the “Page Expired” message. It does not seem to work that way. I found that using the back button would simply show the old (IMO expired) page. In fact in experimenting with different combinations of caching/not caching and expiry times I NEVER managed to get the “Page Expired” message out of the browser.

What conditions provoke that message?

Server Environment ASP .Net. I’ve only tested in IE8 – I’m assuming that other browsers are consistent here.

Answer 1

You can try to set these additional response headers:

Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 
Pragma: no-cache

However, I don’t think there’s any reliable way to force all browsers to not reload a page from history.