新增admin_user表作为后台管理员，程序仿user表做，登陆时跳不去后台，求帮助！ [ 求助交流 ]

1、登陆代码:

public function actionLogin()
{
    $this->layout = 'guest';
    $model = new LoginAdminForm();
    if ($model->load(Yii::$app->request->post()) && $model->login()) {
        return $this->goBack();
    } else {
        return $this->render('login', [
            'model' => $model,
        ]);
    }
}

1、LoginAdminForm代码:

<?php
namespace common\models;

use Yii;
use yii\base\Model;

/**
 * Login form
 */
class LoginAdminForm extends Model
{
    public $username;
    public $password;
    public $rememberMe = true;

    private $_user = false;


    /**
     * @inheritdoc
     */
    public function rules()
    {
        return [
            // username and password are both required
            [['username', 'password'], 'required'],
            // rememberMe must be a boolean value
            ['rememberMe', 'boolean'],
            // password is validated by validatePassword()
            ['password', 'validatePassword'],
        ];
    }

    /**
     * @inheritdoc
     */
    public function attributeLabels()
    {
        return [
            'username' => Yii::t('app', 'Username'),
            'password' => Yii::t('app', 'Password'),
            'rememberMe' => Yii::t('app', 'Remember Me'),
        ];
    }

    /**
     * Validates the password.
     * This method serves as the inline validation for password.
     *
     * @param string $attribute the attribute currently being validated
     * @param array $params the additional name-value pairs given in the rule
     */
    public function validatePassword($attribute, $params)
    {
        if (!$this->hasErrors()) {
            $user = $this->getUser();
            if (!$user || !$user->validatePassword($this->password)) {
                $this->addError($attribute, Yii::t('app', 'Incorrect username or password.'));
            }
        }
    }

    /**
     * Logs in a user using the provided username and password.
     *
     * @return boolean whether the user is logged in successfully
     */
    public function login()
    {
        if ($this->validate()) {
            return Yii::$app->user->login($this->getUser(), $this->rememberMe ? 3600 * 24 * 30 : 0);
        } else {
            return false;
        }
    }

    /**
     * Finds user by [[username]]
     *
     * @return User|null
     */
    public function getUser()
    {
        if ($this->_user === false) {
            $this->_user = AdminUser::findByUsername($this->username);
        }

        return $this->_user;
    }
}

错误：echo 111;可以打印出来，到了goback()，就直接跳回登陆页面。即跳转到/site/index ->site/login。

public function actionLogin()
{
    $this->layout = 'guest';

    

    $model = new LoginAdminForm();
    if ($model->load(Yii::$app->request->post()) && $model->login()) {**echo 1111;exit;**
        return $this->goBack();
    } else {
        return $this->render('login', [
            'model' => $model,
        ]);
    }
}

跟踪发现是一个属性没获取到:文件位置/vendor/yiisoft/yii2/web/respose.php 函数sendContent（）的$this->stream是为null。

请帮忙！谢谢