在我的网络应用程序中,我使用$_SESSIONS,但有时,当用户点击退格键时,他会得到：
Webpage has expired
信息.
为什么会这样？我该怎么做才能避免这种情况？
解决方法:
它还与发送到浏览器的缓存控制指令有关.
查看http://de.php.net/manual/en/session.configuration.php#ini.session.cache-limiter和http://shiflett.org/articles/how-to-avoid-page-has-expired-warnings以了解有关缓存设置的更多信息.
http://shiflett.org/articles/how-to-avoid-page-has-expired-warnings：
Recap
To avoid “Page Has Expired” warnings, set session.cache_limiter to private, and make sure that any form using the POST method submits to an intermediate processing page that redirects the user to a different URL.
