Yii2 使用七 Model添加非表字段属性

<?php
//model
class User extends CActiveRecord
{
    public function getFullname()
    {
        if ($this->first_name && $this->last_name) {
            return $this->first_name . ' ' . $this->last_name;
        }
        return 'Unknown';
    }
}
?>

//view
<span><?php echo $user->fullname ?></span>或
<?=$user->getFullname()?>