Symfony SQLite3和PDO驱动程序

I'm running Symfony but it doesn't find pdo drivers and the demo application throws exception of SQLite3 exceptions.
The configuration checkers says:

PDO should have some drivers installed (currently available: none) Install PDO drivers (mandatory for Doctrine).

But in php.ini I have:

extension=php_pdo_mysql.dll
extension=php_pdo_sqlite.dll
extension=php_sqlite3.dll

In the end, the symfony app says:

// Check if SQLite is enabled
        if ($isDriverException && $this->isSQLitePlatform() && !extension_loaded('sqlite3')) {
            $event->setException(new \Exception('PHP extension "sqlite3" must be enabled because, by default, the Symfony Demo application uses SQLite to store its information.'));
        }

But I knew that with PHP 5.3+ it's installed by default.
I'm running on windows with PHP7.1 installed