不同的字段不会在cakephp 1.3中显示

class User extends AppModel {
    public $name = 'User';
    public $useTable = 'users';
    public $displayField = 'username'; // 设置默认显示字段

    public $fieldsToDisplay = array(
        'username',
        'email'
    );

    public function getFieldsToDisplay() {
        return $this->fieldsToDisplay;
    }
}

class UsersController extends AppController {
    public function index() {
        $this->set('users', $this->User->find('all'));
    }
}

<table>
    <tr>
        <th>Username</th>
        <th>Email</th>
    </tr>
    <?php foreach ($users as $user): ?>
        <tr>
            <td><?php echo $user['User']['username']; ?></td>
            <td><?php echo $user['User']['email']; ?></td>
        </tr>
    <?php endforeach; ?>
</table>