如何在Symfony表单中动态定义字段的类型？

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormEvent;
use Symfony\Component\Form\FormEvents;

class MyFormType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->addEventListener(FormEvents::PRE_SET_DATA, function (FormEvent $event) {
            $form = $event->getForm();
            $data = $event->getData();

            // 根据数据的不同来动态定义字段的类型
            if ($data['field_type'] === 'text') {
                $form->add('field', TextType::class);
            } elseif ($data['field_type'] === 'number') {
                $form->add('field', NumberType::class);
            } else {
                $form->add('field', TextType::class);
            }
        });
    }
}