尝试执行youtube分析API时出现“禁止错误”

I am receiving an error message when trying to execute youtube analytics API.

A service error occurred: Error calling GET https://www.googleapis.com/youtube/analytics/v1/reports?ids=channel%3D%3DUCaayLD9i5x4MmIoVZxXSv_g&start-date=2016-08-01&end-date=2016-08-07&metrics=views&dimensions=7DayTotals: (403) Forbidden

Here is my code:

require_once __DIR__.'\google-api-php-client-1-master\src\Google\autoload.php';
require_once __DIR__.'\google-api-php-client-1-master\src\Google\Client.php';
require_once __DIR__.'\google-api-php-client-1-master\src\Google\Service\YouTube.php';
session_start();
$key = file_get_contents('mykey.json');
$OAUTH2_CLIENT_ID = 'xx-xx-xx';
$OAUTH2_CLIENT_SECRET = 'xxx';
$scope = array("https://www.googleapis.com/auth/youtube.force-ssl", "https://www.googleapis.com/auth/youtubepartner-channel-audit", "https://www.googleapis.com/auth/youtube", "https://www.googleapis.com/auth/youtube.readonly", "https://www.googleapis.com/auth/yt-analytics.readonly", "https://www.googleapis.com/auth/yt-analytics-monetary.readonly","https://www.googleapis.com/auth/youtubepartner");

    $client = new Google_Client();
    $client->setClientId($OAUTH2_CLIENT_ID);
    $client->setClientSecret($OAUTH2_CLIENT_SECRET);
    $client->setAccessType('offline');
    $client->setAccessToken($key);
    $client->setScopes($scope);
      if ($client->getAccessToken()) {        
    //Check to see if our access token has expired. If so, get a new one and save it to file for future use.
        if($client->isAccessTokenExpired()) {
            //refresh your access token if it's expired
            $newToken = json_decode($client->getAccessToken());
            $client->refreshToken($newToken->refresh_token);
            file_put_contents('mykey.json', $client->getAccessToken());
        }

        $analytics = new Google_Service_YouTubeAnalytics($client);
            $channel_url = 'UCaayLD9i5x4MmIoVZxXSv_g';
            $ids = 'channel==' . $channel_url . '';
            $end_date = '2016-08-07';
            $start_date = '2016-08-01';
            $optparams = array(
            'dimensions' => '7DayTotals',
            );
            $metric = 'views';
            $api = $analytics->reports->query($ids, $start_date, $end_date, $metric, $optparams);
            echo '<pre>';print_r($api);die;
  }

I have already enable 'youtube analytic API' and I get the access_token from here

What is wrong with my code ,Or do we need to do some more stuff to get rid from this?

Looking at your code, it seems that you are generating a new access token at the point you save it to file (invalidating the first one).

Try :

  if($client->isAccessTokenExpired()) {
        //refresh your access token if it's expired
        $newToken = json_decode($client->getAccessToken());
        $client->refreshToken($newToken->refresh_token);
        file_put_contents('mykey.json', $newToken);
    }