zend 2.0自定义错误消息？

Question

您好我想将自定义消息添加到错误消息中。这是我的代码。它完全没有用，请你如何检查一下这段代码。

$this->add(array(
                'name' => 'toname',
                'type' => 'Zend\Form\Element\Text',
                'attributes' => array(
                        'id' => 'toname',
                        'class' =>'toname',
                        'required' =>true,
                        'validators' => array(
                                array(
                                        'name' =>'NotEmpty',
                                        'options' => array(
                                                'messages' => array(
                                                        \Zend\Validator\NotEmpty::IS_EMPTY => 'Please enter User Name!'
                                                ),
                                        ),
                                ),
                                array(
                                        'name' => 'StringLength',
                                        'options' => array(
                                                'encoding' => 'UTF-8',
                                                'min' => 4,
                                                'max' => 20,
                                                'messages' => array(
                                                        'stringLengthTooShort' => 'Please enter User Name between 4 to 20 character!',
                                                        'stringLengthTooLong' => 'Please enter User Name between 4 to 20 character!'
                                                ),
                                        ),
                                ),
                        ),
                ),

        ));