PHP-使用Google Gmail OAuth2 API列出消息

我正在创建一个基于web的邮件客户端，它支持使用Google OAuth2 API的Google帐户，登录工作正常，第一次登录时会询问Gmail的权限，但我不知道如何从用户帐户获取邮件。根据，我正在创建一个类来使用这些API，但我不知道如何使用它

class Gmail
{
/*
 * Get list of Messages in user's mailbox.
 * @param  Google_Service_Gmail $service Authorized Gmail API instance.
 * @param  string $userId User's email address. The special value 'me'
 * can be used to indicate the authenticated user.
 * @return array Array of Messages.
 */
    function listMessages($service, $userId) {
        $pageToken = NULL;
        $messages = array();
        $opt_param = array();
        do {
            try {
                if ($pageToken) {
                    $opt_param['pageToken'] = $pageToken;
                }
                $messagesResponse = $service->users_messages->listUsersMessages($userId, $opt_param);
                if ($messagesResponse->getMessages()) {
                    $messages = array_merge($messages, $messagesResponse->getMessages());
                    $pageToken = $messagesResponse->getNextPageToken();
                }
            } catch (Exception $e) {
                print 'An error occurred: ' . $e->getMessage();
            }
        } while ($pageToken);

        foreach ($messages as $message) {
            print 'Message with ID: ' . $message->getId() . '<br/>';
        }

        return $messages;
    }

    function getMessage($service, $userId, $messageId) {
        try {
            $message = $service->users_messages->get($userId, $messageId);
            print 'Message with ID: ' . $message->getId() . ' retrieved.';
            return $message;
        } catch (Exception $e) {
            print 'An error occurred: ' . $e->getMessage();
        }
    }

}

但是我认为这不是正确的方法。。我必须向函数传递什么？ 谢谢

编辑：我已经将添加到我的项目中

---

编辑：已解决，

已解决，我忘记设置并调用$client，现在我的功能是：

function listMessages($userId) {
        $client_id = API_CLIENT_ID;
        $client_secret = API_SECRET;
        $redirect_uri = API_REDIRECT_URL;
        $client = new Google_Client();
        $client->setClientId($client_id);
        $client->setClientSecret($client_secret);
        $client->setRedirectUri($redirect_uri);
        $client->addScope("https://mail.google.com/ https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile ");
        $client->setAccessType("offline");
        $service = new Google_Service_Gmail($client);
        $pageToken = NULL;
        $messages = array();
        $opt_param = array();
        do {
            try {
                if ($pageToken) {
                    $opt_param['pageToken'] = $pageToken;
                }
                $messagesResponse = $service->users_messages->listUsersMessages($userId, $opt_param);
                if ($messagesResponse->getMessages()) {
                    $messages = array_merge($messages, $messagesResponse->getMessages());
                    $pageToken = $messagesResponse->getNextPageToken();
                }
            } catch (Exception $e) {
                print 'An error occurred: ' . $e->getMessage();
            }
        } while ($pageToken);

        foreach ($messages as $message) {
            print 'Message with ID: ' . $message->getId() . '<br/>';
        }

        return $messages;
    }

函数列表消息（$userId）{
$client\u id=API\u client\u id；
$client\u secret=API\u secret；
$redirect\u uri=API\u redirect\u URL；
$client=新的Google_客户端（）；
$client->setClientId（$client\u id）；
$client->setClientSecret（$client\u secret）；
$client->setRedirectUri（$redirect\u uri）；
$client->addScope（“https://mail.google.com/ https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile ");
$client->setAccessType（“脱机”）；
$service=新的Google\u服务\u Gmail（$client）；
$pageToken=NULL；
$messages=array（）；
$opt_param=array（）；
做{
试一试{
如果（$pageToken）{
$opt_param['pageToken']=$pageToken；
}
$messagesResponse=$service->users\u messages->listUsersMessages（$userId，$opt\u param）；
如果（$messagesResponse->getMessages（））{
$messages=array_merge（$messages，$messagesResponse->getMessages（））；
$pageToken=$messagesResponse->getNextPageToken（）；
}
}捕获（例外$e）{
打印“出现错误：”。$e->getMessage（）；
}
}而（$pageToken）；
foreach（$messages作为$message）{
打印“ID为的消息”。$Message->getId（）。
；
}
返回$messages；
}

function listMessages($userId) {
        $client_id = API_CLIENT_ID;
        $client_secret = API_SECRET;
        $redirect_uri = API_REDIRECT_URL;
        $client = new Google_Client();
        $client->setClientId($client_id);
        $client->setClientSecret($client_secret);
        $client->setRedirectUri($redirect_uri);
        $client->addScope("https://mail.google.com/ https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile ");
        $client->setAccessType("offline");
        $service = new Google_Service_Gmail($client);
        $pageToken = NULL;
        $messages = array();
        $opt_param = array();
        do {
            try {
                if ($pageToken) {
                    $opt_param['pageToken'] = $pageToken;
                }
                $messagesResponse = $service->users_messages->listUsersMessages($userId, $opt_param);
                if ($messagesResponse->getMessages()) {
                    $messages = array_merge($messages, $messagesResponse->getMessages());
                    $pageToken = $messagesResponse->getNextPageToken();
                }
            } catch (Exception $e) {
                print 'An error occurred: ' . $e->getMessage();
            }
        } while ($pageToken);

        foreach ($messages as $message) {
            print 'Message with ID: ' . $message->getId() . '<br/>';
        }

        return $messages;
    }