PHP - 使用可下载的URL返回响应

I am trying for hours to figure out how to return my csv file trough URL in response. The csv file is there, url is matched but I don't know how can I return downloadable url in my response.

  $rootDir = $this->container->get('kernel')->getRootDir();
  $dir = $rootDir . '/../web/uploads/news/';

  /// - rest of the code that is not relevant and generates my csv $fileName

  $fp = fopen($fileName, 'w');

In this part I am trying to set my response headers and downloadable url with no luck:

 $baseurl = $request->getScheme() . '://' . $request->getHttpHost()
. $request->getBasePath() . $dir . $fileName;


    // Set response
    $response = new BinaryFileResponse($dir .DIRECTORY_SEPARATOR. $fileName);

    // Set headers
    $d = $response->headers->makeDisposition(
        ResponseHeaderBag::DISPOSITION_ATTACHMENT,
         $fileName
    );
    $response->headers->set('Content-Disposition', $d);

    return $this->success();

    $response = new BinaryFileResponse($pathToFile);
    $response->setContentDisposition(
        ResponseHeaderBag::DISPOSITION_ATTACHMENT,
        'filenameThatWillBeDownloaded.yourextension'
    );

    return $response;

dont forget to import the classes

use Symfony\Component\HttpFoundation\BinaryFileResponse;
use Symfony\Component\HttpFoundation\ResponseHeaderBag;