我几乎搜索了谷歌首页的所有结果。但似乎找不到答案。我正在使用谷歌API提供的刷新令牌，并收到：

Error refreshing the OAuth2 token, message: '{ "error" : "invalid_grant" }

我在做什么。第一：我正在创建并存储到google api的持久连接：

$client = new Google_Client();
$client->setClientId('xxxxxx-s73q0pa41aq3i2kcpatmpas6e6kkp99h.apps.googleusercontent.com');
$client->setClientSecret('xxxxxxxxxxxx');
$client->setRedirectUri('http://xxxxxxxx/generaterefreshtoken.php');
$client->setScopes(array('https://www.googleapis.com/auth/drive'));
$client->setAccessType('offline');


if (isset($_GET['code'])) {
  $client->authenticate();
  $_SESSION['token'] = $client->getAccessToken();
  $redirect = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'];
  header('Location: ' . filter_var($redirect, FILTER_SANITIZE_URL));
}

if (isset($_SESSION['token'])) {
 $client->setAccessToken($_SESSION['token']);
}

if (isset($_REQUEST['logout'])) {
  unset($_SESSION['token']);
  $client->revokeToken();
}

if ($client->getAccessToken()) {

    $jsonarray = json_decode($client->getAccessToken());
    $arrGoogleAuth['access_token']=$jsonarray->access_token;
    $arrGoogleAuth['refresh_token']=$jsonarray->refresh_token;
    //filewrite

    $myFile = "refreshtoken.conf";
    $fh = fopen($myFile, 'w') or die("can't open file");
    fwrite($fh, $client->getAccessToken());
    fclose($fh);


    /*

    die();

    $service = new Google_DriveService($client);
    $file = new Google_DriveFile();
    $file->setTitle('My document.txt');
    $file->setDescription('A test document');
    $file->setMimeType('text/plain');

    $data = file_get_contents('document.txt');

    $createdFile = $service->files->insert($file, array(
          'data' => $data,
          'mimeType' => 'text/plain',
        ));

    print_r($createdFile);
*/



  // The access token may have been updated lazily.
  $_SESSION['token'] = $client->getAccessToken();
} else {
  $auth = $client->createAuthUrl();
  header("Location: $auth");
}

因此，基本上一切都在运行，令牌存储在一个文本文件中：

{
"access_token":"xxxxxxxxxxxxxxxN4U0ys2wy5monxs0Xh5fu5ayKL0OIENo-d1sN6g3YA",
"token_type":"Bearer",
"expires_in":3600,
"refresh_token":"xxxxxxxxxxxxDON-l90BNUcJgnkfZWDfg",
"created":1358120143
}

当我尝试使用以下代码进行身份验证时：

$client = new Google_Client();
$client->setClientId($googleDriveConfig['clientid']);
$client->setClientSecret($googleDriveConfig['clientsecret']);
$client->setRedirectUri(curPageURL);
$client->setScopes(array('https://www.googleapis.com/auth/drive'));
$client->refreshToken(file_get_contents('../_config/refreshtoken.conf'));
$client->authenticate();

我得到以下错误：刷新OAuth2令牌时出错，消息：“{“错误”：“invalid_grant”}