我正试图用这段代码获得access token，但没有成功。我检查了每一次卷曲操作，每一件事都很好。但仍然无法获得令牌。
这是来自谷歌的OAuth2指南
$data_string = "code=" . $_REQUEST['code'] . "&client_id=" . $client_id . "&client_secret=" . $client_secret . "&redirect_uri=" . $redirect . "&grant_type=authorization_code";
$ch = curl_init();
curl_setopt($ch,CURLOPT_URL,'https://accounts.google.com/o/oauth2/token');
curl_setopt($ch,CURLOPT_POST,TRUE);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,TRUE);
curl_setopt($ch,CURLOPT_HTTPHEADER,array('Content-type: application/x-www-form-urlencoded'));
curl_setopt($ch,CURLOPT_POSTFIELDS,$data_string);
$response = curl_exec($ch);
curl_close($ch);
//$data = json_decode($response);
print_r($response);
$data_string = "code=" . $_REQUEST['code'] . "&client_id=" . $client_id . "&client_secret=" . $client_secret . "&redirect_uri=" . $redirect . "&grant_type=authorization_code";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,'https://accounts.google.com/o/oauth2/token');
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
curl_setopt($ch, CURLOPT_AUTOREFERER, TRUE);
curl_setopt($ch, CURLOPT_POST,TRUE);
curl_setopt($ch, CURLOPT_POSTFIELDS,$data_string);
curl_setopt($ch, CURLOPT_VERBOSE, TRUE);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,TRUE);
curl_setopt($ch, CURLOPT_HTTPHEADER,array('Content-type: application/x-www-form-urlencoded'));
$response = curl_exec($ch);
curl_close($ch);
请记住，如果您在URL中使用HTTPS，则必须添加代码：
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);