检查用户是否登录了新的Facebook API

$curl = curl_init();
curl_setopt_array($curl, array(
    CURLOPT_URL => "https://graph.facebook.com/oauth2.0/access_token?client_id=<your_client_id>&client_secret=<your_client_secret>&grant_type=client_credentials",
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POSTFIELDS => array(
        "grant_type" => "client_credentials",
        "client_id" => "<your_client_id>",
        "client_secret" => "<your_client_secret>",
        "redirect_uri" => "<your_redirect_uri>"
    )
));
$response = curl_exec($curl);
curl_close($curl);
$data = json_decode($response, true);
if ($data['issued_to'] == "<your_client_id>" && $data['audience'] == "<your_client_id>") {
    // The user has authorized your application
} else {
    // The user has not authorized your application
}