如何在Symfony 4中的一个控制器中将参数从一个函数传递到另一个函数？

use Symfony\Component\HttpFoundation\Request;

class MyController extends AbstractController
{
    private $myService;

    public function __construct(MyService $myService)
    {
        $this->myService = $myService;
    }

    public function myAction(Request $request)
    {
        $param = $request->query->get('param');
        $result = $this->myService->process($param);
        // ...
    }
}

# config/routes.yaml
my_route:
    path: '/my-route/{param}'
    controller: App\Controller\MyController::myAction

use Symfony\Component\HttpFoundation\Request;

class MyController extends AbstractController
{
    public function myAction(Request $request, $param)
    {
        $result = $this->myService->process($param);
        // ...
    }
}

use Symfony\Component\HttpFoundation\Request;

class MyController extends AbstractController
{
    public function myAction(Request $request)
    {
        $param = $request->query->get('param');
        $result = $this->myService->process($param);
        // ...
    }
}