如何上传文件

// src/AppBundle/Entity/Product.php
namespace AppBundle\Entity;
 
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
 
class Product
{
    // ...
 
    /**
     * @ORM\Column(type="string")
     *
     * @Assert\NotBlank(message="Please, upload the product brochure as a PDF file.")
     * @Assert\File(mimeTypes={ "application/pdf" })
     */
    private $brochure;
 
    public function getBrochure()
    {
        return $this->brochure;
    }
 
    public function setBrochure($brochure)
    {
        $this->brochure = $brochure;
 
        return $this;
    }
}

// src/AppBundle/Form/ProductType.php
namespace AppBundle\Form;
 
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\Form\Extension\Core\Type\FileType;
 
class ProductType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            // ...
            ->add('brochure', FileType::class, array('label' => 'Brochure (PDF file)'))
            // ...
        ;
    }
 
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => 'AppBundle\Entity\Product',
        ));
    }
}

// src/AppBundle/Controller/ProductController.php
namespace AppBundle\ProductController;
 
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use AppBundle\Entity\Product;
use AppBundle\Form\ProductType;
 
class ProductController extends Controller
{
    /**
     * @Route("/product/new", name="app_product_new")
     */
    public function newAction(Request $request)
    {
        $product = new Product();
        $form = $this->createForm(ProductType::class, $product);
        $form->handleRequest($request);
 
        if ($form->isSubmitted() && $form->isValid()) {
            // $file stores the uploaded PDF file
            /** @var Symfony\Component\HttpFoundation\File\UploadedFile $file */
            $file = $product->getBrochure();
 
            // Generate a unique name for the file before saving it
            $fileName = md5(uniqid()).'.'.$file->guessExtension();
 
            // Move the file to the directory where brochures are stored
            $file->move(
                $this->getParameter('brochures_directory'),
                $fileName
            );
 
            // Update the 'brochure' property to store the PDF file name
            // instead of its contents
            $product->setBrochure($fileName);
 
            // ... persist the $product variable or any other work
 
            return $this->redirect($this->generateUrl('app_product_list'));
        }
 
        return $this->render('product/new.html.twig', array(
            'form' => $form->createView(),
        ));
    }
}

# app/config/config.yml
 
# ...
parameters:
    brochures_directory: '%kernel.root_dir%/../web/uploads/brochures'

// src/AppBundle/FileUploader.php
namespace AppBundle;
 
use Symfony\Component\HttpFoundation\File\UploadedFile;
 
class FileUploader
{
    private $targetDir;
 
    public function __construct($targetDir)
    {
        $this->targetDir = $targetDir;
    }
 
    public function upload(UploadedFile $file)
    {
        $fileName = md5(uniqid()).'.'.$file->guessExtension();
 
        $file->move($this->targetDir, $fileName);
 
        return $fileName;
    }
}

// src/AppBundle/Controller/ProductController.php
 
// ...
public function newAction(Request $request)
{
    // ...
 
    if ($form->isValid()) {
        $file = $product->getBrochure();
        $fileName = $this->get('app.brochure_uploader')->upload($file);
 
        $product->setBrochure($fileName);
 
        // ...
    }
 
    // ...
}

// src/AppBundle/EventListener/BrochureUploadListener.php
namespace AppBundle\EventListener;
 
use Symfony\Component\HttpFoundation\File\UploadedFile;
use Doctrine\ORM\Event\LifecycleEventArgs;
use Doctrine\ORM\Event\PreUpdateEventArgs;
use AppBundle\Entity\Product;
use AppBundle\FileUploader;
 
class BrochureUploadListener
{
    private $uploader;
 
    public function __construct(FileUploader $uploader)
    {
        $this->uploader = $uploader;
    }
 
    public function prePersist(LifecycleEventArgs $args)
    {
        $entity = $args->getEntity();
 
        $this->uploadFile($entity);
    }
 
    public function preUpdate(PreUpdateEventArgs $args)
    {
        $entity = $args->getEntity();
 
        $this->uploadFile($entity);
    }
 
    private function uploadFile($entity)
    {
        // upload only works for Product entities
        if (!$entity instanceof Product) {
            return;
        }
 
        $file = $entity->getBrochure();
 
        // only upload new files
        if (!$file instanceof UploadedFile) {
            return;
        }
 
        $fileName = $this->uploader->upload($file);
        $entity->setBrochure($fileName);
    }
}