Symfony FromEvents 1 参数必须是

Question

这里的错误不是明确的，从我认为它只是与参数之间的类型差异有关，但我还没有找到解决这个问题的方法......EventListener正在接收 2 个参数，但它没有提供哪个参数的信息它们是该问题的“1”参数，但我认为它是第二个，因为错误表示UserBundle\Form\FormEvent的单数实例，第一个参数是FormEvents复数类中的通用事件。

错误显示：

类型错误：传递给 UserBundle\Form\UserType::UserBundle\Form{closure}() 的参数 1 必须是 UserBundle\Form\FormEvent 的一个实例，Symfony\Component\Form\FormEvent 的实例给定

<?php

namespace UserBundle\Form;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\Extension\Core\Type\HiddenType;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\Extension\Core\Type\SubmitType;
use Symfony\Component\Form\Extension\Core\Type\EmailType;
use Symfony\Component\Form\Extension\Core\Type\PasswordType;
use Symfony\Component\Form\Extension\Core\Type\RepeatedType;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\Form\FormEvents;
class UserType extends AbstractType
{
    /**
     * {@inheritdoc}
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
        ->add('username',HiddenType::class)
        ->add('firstname',TextType::class)
        ->add('lastname',TextType::class)
        ->add('email', RepeatedType::class, 
            array('type' => EmailType::class, 'invalid_message' => 'The email fields must match.','options' 
                => array('attr' => array('class' => 'email-field')),'required' => true, 'first_options'  
                => array('label' => 'Email'),'second_options' => array('label' => 'Confirm email'),))
        ->add('password', RepeatedType::class, 
            array('type' => PasswordType::class, 'invalid_message' => 'The password fields must match.','options' 
                => array('attr' => array('class' => 'password-field')),'required' => true, 'first_options'  
                => array('label' => 'Password'),'second_options' => array('label' => 'Confirm password'),))
        ->add('save',SubmitType::class)
        ->addEventListener(FormEvents::PRE_SUBMIT, function(FormEvent $event) {
            $data = $event->getData();
            $form = $event->getForm();
            if ($data['firstname'] !== null && $data['lastname'] !== null){
                $username = $data['firstname']." ".$data['lastname'];
                $data['username'] = $username;
                $event->setData($data); 
            }
        });
    }

    /**
     * {@inheritdoc}
     */
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => 'UserBundle\Entity\User'
        ));
    }

    /**
     * {@inheritdoc}
     */
    public function getBlockPrefix()
    {
        return 'user';
    }


}

我已经按照 symfony 文档给出的步骤

Answer 1

您缺少FormEvent类导入。

use Symfony\Component\Form\FormEvent;

由于您没有导入它，它使用了类 ( UserBundle\Form\FormEvent)的当前命名空间。但是这个类不存在。