Session似乎总是过期而无法恢复会话值

Question

I developed an app that needs users sign in. And the app keeps the session_id in the sandbox, so I just hope when session_id posted to the server, user_id can be get again by $_SESSION['id'].

Here's the code:

session_id($_POST["session_id"]);  
session_start();

$user_id = session_id($_POST["user_id"]); 

If users sign in, users can get the data they need in about 4 hours. But after several hours, users can not get any data.

I found it's because session_id($_POST["user_id"]) = nil.

I have set the session_gc_maxlifetime to 999999999. I restart the server.

However it doesn't work.

Answer 1

You need to session_start(); before anything else so session_start(); should be the very first line of your code.