Symfony-在表单的EventSubscriber中注入实体管理器 - Symfony - Inject Entity Manager in EventSubscriber of form

Symfony - Inject Entity Manager in EventSubscriber of form

这是我第一次使用表单的EventListener，所以我很难在其中注入EntityManager。

我有一个名为UserType的formType，在这个类中我有一个子EventSubscriber AddDepartmentDegreeCourseFieldSubscriber，它需要访问EntityManager

class UserType extends AbstractType
{
    /**
     * @param FormBuilderInterface $builder
     * @param array $options
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->addEventSubscriber(new AddProfileFieldSubscriber());
        $builder->addEventSubscriber(new AddDepartmentDegreeCourseFieldSubscriber());
    }
    /**
     * @param OptionsResolver $resolver
     */
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => 'AppBundle'Entity'User'
        ));
    }
}

这是我的services.yml

app.department_course_degree_subscriber:
    class: AppBundle'Form'EventListener'AddDepartmentDegreeCourseFieldSubscriber
    arguments: ["@doctrine.orm.entity_manager"]
    tags:
        - { name: kernel.event_subscriber }

我得到的错误如下

可捕获的致命错误：参数1传递给AppBundle''Form''EventListener''AddDepartmentDegree CourseFieldSubscriber:：__construct（）必须是Doctrine''ORM''EntityManager的实例，未给定，调用在/Users/shairyar/Sites/oxford portal/src/AppBundle/Form/UserType.php中在第21行并定义

我知道这个错误意味着什么，但我认为我在services.yml中注册的服务应该注入EntityManager，所以我为什么会出现这个错误？我在这里错过了什么？任何帮助都将不胜感激。

这是因为，在构建表单时传递AddDepartmentDegreeCourseFieldSubscriber的新实例。您需要从服务容器传递实例。

use AppBundle'Form'EventListener'AddDepartmentDegreeCourseFieldSubscriber;
class UserType extends AbstractType
{
    private $addDepartmentDegreeCourseFieldSubscriber;
    public function __construct(AddDepartmentDegreeCourseFieldSubscriber $subscriber)
    {
        $this->addDepartmentDegreeCourseFieldSubscriber = $subscriber;
    }
    /**
     * @param FormBuilderInterface $builder
     * @param array $options
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->addEventSubscriber($this->addDepartmentDegreeCourseFieldSubscriber);
    }
}

# app/config/services.yml
services:
    app.department_course_degree_subscriber:
        class: AppBundle'Form'EventListener'AddDepartmentDegreeCourseFieldSubscriber
        arguments: ["@doctrine.orm.entity_manager"]
        tags:
            - { name: kernel.event_subscriber }
    app.form.type.my_user_form:
        class: AppBundle'Form'UserType
        arguments: [ "@app.department_course_degree_subscriber" ]
        tags:
            - { name: form.type }