add_meta_box : Pass Params to Callback?

Hello Community,

I need to pass some Params to “my_callback”:
<?php add_meta_box( $id, $title, ‘my_callback’, $page, $context, $priority ); ?>

First try was something like this:

function my_callback() {
global $params;
}

function add_my_meta_box() {
global $param;
$param = 'somevalue';
add_meta_box( $id, $title, <strong>'my_callback'</strong>, $page, $context, $priority );
}

Did not work…

Next try was to wrap it up in a Class to pass the params like
$this->param = 'somevalue';
Good plan, but when it came to my_callback, I tried something like

'my_class::my_callback' or
array ($this, 'my_callback') or
'$this->my_callback()'

Yes, I know, some things I tried are stupid, but I did… so what…

I finally came up with

$_SESSION['MYPARAM'] = 'somevalue';

At least, it works. But I don′t like it.
Is there any way to pass params to my_callback, or use add_meta_box from within a class?

Thanks in advance!

Best regards

Udo