在子域之间共享PHP中的会话变量

我想使用许多子域在PHP中共享我的会话变量。我有一个例子：

I want to share my session variables in PHP using many subdomains. I have that example :

• example.com


• subdomain1.example.com

我尝试在两个域之间使用相同的会话变量。我已经在PHP中测试了很多功能，但没有任何效果。这是我的测试方法：

I try to use the same session variables between the two domains. I already tested a lot of functions in PHP but nothing work. Here is my way to test :

在example.com/page.php上，我进行了测试：

On the example.com/page.php, I have that test :

echo '<pre>';
var_dump(session_set_cookie_params(0, '/', '.example.com')); 
session_start(); 
echo "Session ID : ".session_id()."\n";
$_SESSION['foo'] = 'bar';
print_r($_SESSION);

在subdomain1.example.com/page.php上，我有一个：

And on subdomain1.example.com/page.php, I have that one :

echo '<pre>';
session_set_cookie_params(0, '/', '.example.com');
session_start();
echo "Session ID : ".session_id()."\n";
print_r($_SESSION);

我可以看到两个页面之间的会话ID相同，但是会话变量不可能在subdomain1.example.com/page.php

I can see that the session id is the same between the two pages, but session variables are impossible to read in subdomain1.example.com/page.php

我测试了许多功能，例如为会话设置名称，但没有更多结果。

I tested many functions, like set a name to the session, but with no more results.

谢谢。