What should I do if the webpage has expired?

When we use the IE back button or historygo (-1) in the webpage, we will see a cache page. However, after session_start is used, this function will force the current page not to be cached, export

Click the back button of IE or the history in the webpage. go (-1), we will see the cache page, but after session_start is used, this function will force the current page not to be cached, resulting in "warning: the webpage has expired ".

Solution 1:Add one sentence after session_start

Header ("Cache-control: private ");

Note that the program cannot have any output before that.

Solution 2:Before session_start, add

Session_cache_limiter ('private'); // do not clear the form, only during the effective period of the session

Session_cache_limiter has two meanings:

Session_cache_limiter ('nocache'); // clear the form

Session_cache_limiter ('public'); // do not clear the form, as if no session is used

Solution 3:Change the configuration file php. ini

Change session. cache_limiter = nocache to session. cache_limiter = or session. cache_limiter = none, and restart apache.