如何在具有相对路径的多个目录/子目录中使用 PHP 包含

I'm having difficulty with paths in a cms system I'm attempting to build, I've basically got a folder with my header.php and footer.php files inside.

These are included in index.php and work fine. But then when I attempt to use the same includes in a file within my admin sub directory, the images and CSS are broken, obviously because the relative path is now wrong.

So my question is, how can I overcome this?

After reading some of the other questions on here and various other sources, I think absolute paths are the way forward, but I've always used relative paths, so the various concepts of using config files to specify an absolute path are confusing me.

I usually manage to work things out for myself, but it's been a long day and Im stumped!

解决方案

i usualy have a file called config in my application root and in it i define a constant for base path and a few others:

define('APP_BASE_PATH', dirname(__FILE__));
define('APP_FUNCTIONS_PATH', APP_BASE_PATH . '/functions');

and i include my files like

include (APP_BASE_PATH . 'includes/another_file.php');
include (APP_FUNCTIONS_PATH . '/function_file.php');

that way i can place my aplication in whatever directory, plus i can move files around without to much worries.

also using full path makes the include faster