尝试使用ContainerAwareInterface时容器未设置

Question

对于Symfony 2.8，此代码$this->container为空。

use Symfony\Component\DependencyInjection\ContainerAwareInterface; 
use Symfony\Component\DependencyInjection\ContainerAwareTrait; 

class EntrarYPreregistroFormSubscriber implements EventSubscriberInterface, ContainerAwareInterface 
{ 
    use ContainerAwareTrait; 

    public function preSetData(FormEvent $event) 
    { 
     $l = $this->container->get('logger'); 
     $l->notice('GOT LOGGER'); 
    } 

    .... 
} 

而且我EntrarYPreregistroFormSubscriber服务被配置为：

pmktconcursos.entrarypreregistro.form.subscriber: 
    class: PMKT\ConcursosBundle\EventListener\EntrarYPreregistroFormSubscriber 
    calls: 
     - [ setContainer,[ "@service_container" ] ] 

我得到异常的$l = $this->container->get('logger');

request.CRITICAL: Uncaught PHP Exception Symfony\Component\Debug\Exception\FatalErrorException: "Error: Call to a member function get() on a non-object" at /Users/vmarquez/Proyectos/GrupoPMKT/Promoticket/current/dev/chedraui1607/chedraui1607/src/PMKT/ConcursosBundle/Form/EventListener/EntrarYPreregistroFormSubscriber.php line 30 {"exception":"[object] (Symfony\\Component\\Debug\\Exception\\FatalErrorException(code: 0): Error: Call to a member function get() on a non-object at /Users/vmarquez/Proyectos/GrupoPMKT/Promoticket/current/dev/chedraui1607/chedraui1607/src/PMKT/ConcursosBundle/Form/EventListener/EntrarYPreregistroFormSubscriber.php:30)"} 

我缺少的东西？

Answer 1

您正在制作表单事件监听器，因此在您的表单类型中，您有类似于$builder->addEventSubscriber(new EntrarYPreregistroFormSubscriber());的内容，因此您可以看到，表单事件监听器与常规事件监听器略有不同。因为你是创建对象的人，所以你应该打电话给setContainer($serviceContainer)。要做到这一点，你应该在你的表单类型中有服务容器。要做到这一点，你应该通过它作为选项，同时在控制器中创建你的表格

// in controller 
$object = ...; 
$form = $this->createForm(new YourFormType(), $object, array('service_container' => $this->get('service_container'))); 

// in YourFormType 
$listener = new EntrarYPreregistroFormSubscriber(); 
$listener->setContainer($options['service_container']); 
$builder->addEventSubscriber($listener); 
... 
// in setDefaultOptions method 
public function setDefaultOptions(OptionsResolverInterface $resolver) 
{ 
    $resolver->setDefaults(array(
     ... 
     'service_container' => null, 
    )); 
}