如何使用createnamebuilder为表单验证symfony添加动态错误？

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Validator\Constraints as Assert;

class MyFormType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('name', null, [
                'constraints' => [
                    new Assert\NotBlank(),
                    new Assert\Length(['min' => 3]),
                ],
            ])
            // 添加其他表单字段
            // ...
        ;
    }
}

use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\Annotation\Route;

class MyController extends AbstractController
{
    /**
     * @Route("/submit-form", name="submit_form", methods={"POST"})
     */
    public function submitForm(Request $request)
    {
        $form = $this->createForm(MyFormType::class);
        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {
            // 处理表单提交
        } else {
            $errors = $form->getErrors(true, false); // 获取表单错误

            foreach ($errors as $error) {
                $field = $error->getOrigin()->getName(); // 获取错误对应的字段名
                $errorMessage = $error->getMessage(); // 获取错误消息

                $form->get($field)->addError(new FormError($errorMessage)); // 使用createNameBuilder方法添加动态错误
            }
        }

        // 渲染模板并返回响应
    }
}