Symfony 3.2:OneToMany 集合未初始化

Question

Entity/User.php：

    // ...
    use DoctrineCommonCollectionsArrayCollection;
    // ...
    /**
     * @var ArrayCollection
     *
     * @ORMOneToMany(targetEntity="Picture", mappedBy="user")
     * @ORMOrderBy({"file" = "ASC"})
     **/
    private $pictures;
    /**
     * Constructor
     */
    public function __construct()
    {
        $this->pictures = new DoctrineCommonCollectionsArrayCollection();
    }
    /**
     * Add picture
     *
     * @param MyBundleEntityPicture $picture
     *
     * @return User
     */
    public function addPicture(MyBundleEntityPicture $picture)
    {
        $this->pictures[] = $picture;
        return $this;
    }
    /**
     * Remove picture
     *
     * @param MyBundleEntityPicture $picture
     */
    public function removePicture(MyBundleEntityPicture $picture)
    {
        $this->pictures->removeElement($picture);
    }
    /**
     * Get pictures
     *
     * @return DoctrineCommonCollectionsCollection
     */
    public function getPictures()
    {
        return $this->pictures;
    }
   // ...

实体/图片.php

// ...
/**
 * @var ArrayCollection
 *
 * @ORMManyToOne(targetEntity="User", inversedBy="pictures")
 * @ORMJoinColumn(name="user", referencedColumnName="id")
 */
private $user;
/**
 * Set user
 *
 * @param MyBundleEntityUser $user
 *
 * @return Picture
 */
public function setUser(MyBundleEntityUser $user = null)
{
    $this->user = $user;
    return $this;
}
/**
 * Get user
 *
 * @return MyBundleEntityUser
 */
public function getUser()
{
    return $this->user;
}
// ...

控制器

/图片控制器.php：

// ...
public function indexAction(Request $request)
    {
        return array(
            'pictures' => $this->getUser()->getPictures(),
        );
    }
// ...

这是我转储->getPictures（）的结果时Symfony的分析器输出的内容：

PersistentCollection {#292 ▼
  -snapshot: []
  -owner: User {#270 ▶}
  -association: array:16 [ …16]
  -em: EntityManager {#53 …11}
  -backRefFieldName: "user"
  -typeClass: ClassMetadata {#272 …}
  -isDirty: false
  #collection: ArrayCollection {#293 ▶}
  #initialized: false
}

不知何故，集合没有初始化并且没有项目，尽管数据库中有一些......我在这里错过了什么？

Answer 1

将其添加到您的教义注释中，使其延迟加载相关实体;

@ORM\OneToMany（targetEntity="Picture"， mappedBy="user"，fetch="EAGER"）