YII2.0后台如何手动添加用户功能？又是用哪种类来实现的？

<?php
namespace backend\models;use yii\base\Model;
use common\models\Adminuser;use yii\helpers\VarDumper;
/**
 * Signup form 
 */
 class SignupForm extends Model
{    public $username;    
public $email;    
public $password;    
public $password_repeat;    
public $nickname;    public $phone;    
  /**
   * {@inheritdoc}     
  */
    public function rules()
    {        return [
            ['username', 'trim'],
            ['username', 'required'],
            ['username', 'unique', 'targetClass' => '\common\models\Adminuser', 'message' => '用户名已存在！'],
            ['username', 'string', 'min' => 2, 'max' => 255],

            ['email', 'trim'],
            ['email', 'required'],
            ['email', 'email'],
            ['email', 'string', 'max' => 255],
            ['email', 'unique', 'targetClass' => '\common\models\Adminuser', 'message' => '邮箱已存在！'],

            ['password', 'required'],
            ['password', 'string', 'min' => 6],
            ['password_repeat', 'required'],
            ['password_repeat', 'compare','compareAttribute'=>'password','message'=>'两次输入的密码不一致'],

            ['nickname', 'required'],
            ['email', 'string', 'max' => 128],

            ['phone', 'required'],
            [['phone'], 'unique','targetClass' => '\common\models\Adminuser','message'=>'{attribute}已经被占用了'],
            ['phone','match','pattern'=>'/^1[0-9]{10}$/','message'=>'{attribute}必须为1开头的11位纯数字'],
        ];
    }    public function attributeLabels()
    {        return [            'id' => 'ID',
            'username' => '用户名',
            'password' => '密码',
            'password_repeat' => '再次输入密码',
            'email' => '邮箱',
            'nickname' => '昵称', 
            'phone' => '手机号', 
        ];
    }    
    /**
     * Signs user up.
     *
     * @return User|null the saved model or null if saving fails     
     */
    public function signup()
    {        if (!$this->validate()) {            
    return null;
        }        
        $user = new Adminuser();        
        $user->username = $this->username;        
        $user->nickname = $this->nickname;        
        $user->phone = $this->phone;        
        $user->email = $this->email;        
        $user->setPassword($this->password);        
        $user->generateAuthKey();        
        $user->created_at = time();        
        $user->updated_at = time();        
        /*
        //保存调试
        $user->save();
        VarDumper::dump($user->errors);
        exit(0);        */
        return $user->save() ? $user : null;
    }
}

<?php
use yii\helpers\Html;
use yii\widgets\ActiveForm;
/* @var $this yii\web\View */
/* @var $model common\models\Adminuser */
$this->title = 'Create Adminuser';
$this->params['breadcrumbs'][] = ['label' => 'Adminusers', 'url' => ['index']];
$this->params['breadcrumbs'][] = $this->title;
?>
<p class="adminuser-create">

    <h1><?= Html::encode($this->title) ?></h1>

   <?php $form = ActiveForm::begin(); ?>

    <?= $form->field($model, 'username')->textInput(['maxlength' => true]) ?>

    <?= $form->field($model, 'password')->passwordInput(['maxlength' => true]) ?>
    <?= $form->field($model, 'password_repeat')->passwordInput(['maxlength' => true]) ?>
    <?= $form->field($model, 'email')->textInput(['maxlength' => true]) ?>

    <?= $form->field($model, 'nickname')->textInput(['maxlength' => true]) ?> 
    <?= $form->field($model, 'phone')->textInput(['maxlength' => true]) ?> 
    <p class="form-group">
        <?= Html::submitButton('Save', ['class' => 'btn btn-success']) ?>
    </p>

    <?php ActiveForm::end(); ?>


</p>

<?php   
public function actionCreate()
    {        $model = new SignupForm();        
    if ($model->load(Yii::$app->request->post())) {            
    if($user = $model->signup()){                
    return $this->redirect(['view', 'id' => $model->id]); 
            }
            
        }        return $this->render('create', [            
        'model' => $model,
        ]);
    }