在symfony 2.1中不工作注释有效性

Question

实体属性：

 /**
 * @var string $content
 *
 * @ORMColumn(name="content", type="string", length=300)
 * @AssertNotBlank(message="Please enter question")
 * @AssertLength(
 *   min = "15",
 *   max = "300",
 *   minMessage = "Text question must be larger than 15 symbol",
 *   maxMessage = "Text question must be less than 300 symbol"
 * )
 */
protected $content;

表格提交（在控制器中）：

// Add questions
if ($request->getMethod() === 'POST') {
  $formQuestion->bind($request);
  if ($formQuestion->isValid()) {
    // Here code save question
  }
  else {
    $errors = $formQuestion->getErrors():
    // Null array ((
  }
}

没有错误显示（（（为什么不阅读注释验证。其他属性是良好的验证。

Answer 1

 is you set form reset tag in your twig template 
like this 
 {{ form_rest(form) }}