问：为什么我会得到“未定义索引: oauth_token”( Jim .(编码)

EN

public function access_youtube()
{ //STEP 2

// Here is the first call to load the library 
    $params['key'] = 's390075769.onlinehome.fr';
    $params['secret'] = 'iHD72YKzWmbm8VTwncht_E-d';

// We  can change the signing algorithm and http method by setting the following in your params array.
    $params['algorithm'] = 'HMAC-SHA1';
    // $params['method'] = "GET";

// We need to reload the library since we left our site beetween Step 1 & 2.
    $this->load->library('google_oauth', $params);

// We are using HMAC signing you need to specify the token_secret you got from the request step as the second parameter of this method. So
    $token_secret = $this->session->userdata('token_secret');
    $oauth = $this->google_oauth->get_access_token(false, $token_secret);

// The access method will return an array with keys of ‘oauth_token’, and ‘oauth_token_secret’ 
// These values are your access token and your access token secret. We should store these in our database.  
    $this->session->set_userdata('oauth_token', $oauth['oauth_token']);
    $this->session->set_userdata('oauth_token_secret', $oauth['oauth_token_secret']);

// Now you have an access token and can make google service requests on your users behalf
    redirect(site_url());
}

class Example extends CI_Controller
{
private $CI;
public function __construct()
{
     parent::__construct();

    $this->CI =& get_instance();
    $this->CI->load->library('session');

    $oauth = array();
    $oauth['oauth_token_secret']='';
    $oauth['oauth_token']='';

}