How do I deactivate caching in browsers?

问题

For instance, if you exit your Yahoo mail and then click the back button, it will not load the last page, it will redirect you to the login page.

I have to do this with my PHP code, I'm using CodeIgniter.

Some friends told me to disable caching but that will be a bad thing because I have a lot of images in my system and it would be bad to download them every time.

How do I do this with PHP?

回答1:

Disable caching of your page with the following code :

http://php.net/manual/en/function.header.php

<?php
header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past
?>

回答2:

Try these:

<?php
header("Expires: Fri, 01 Jan 2010 05:00:00 GMT");
header( 'Last-Modified: ' . gmdate( 'D, d M Y H:i:s' ) . ' GMT' );
header( 'Cache-Control: no-store, no-cache, must-revalidate' );
header( 'Cache-Control: post-check=0, pre-check=0', false );
header( 'Pragma: no-cache' ); 
?>

回答3:

The simple answer to avoid caching on the client browsers is to configure the Cache-Control HTTP response header.

http://en.wikipedia.org/wiki/List_of_HTTP_header_fields#Avoiding_caching

However, I don't have a PHP snippet with me to show you how to do it exactly. It should as simple getting the HTTP response object, and setting a header "Cache-Control" with value "no-store, must-revalidate"

来源：https://stackoverflow.com/questions/6017231/how-do-i-deactivate-caching-in-browsers