yii 安装完毕，介绍一款帅气的后台模版 adminLTE
git地址： https://github.com/dmstr/yii2-adminlte-asset

安装参考 ReadMe

php composer.phar require dmstr/yii2-adminlte-asset "2.*"

安装完成后修改配置文件： backend/config/main.php 添加代码：

'view' => [
    'theme' => [
        'pathMap' => [
            '@app/views' => '@vendor/dmstr/yii2-adminlte-asset/example-views/yiisoft/yii2-app'
        ],
    ],
],

但是这样不利于我们之后对它的修改，所以复制yii2-adminlte的 layout 和 site到 backend/views 下，删除上面的配置也可以达到效果。

分离后台用户

首先创建后台用户表：
执行命令：

yii migrate/create admin_user

然后修改生成的 迁移文件：

public function up()
    {
        $this->createTable('admin_user', [
            'id' => $this->primaryKey(),
            'username' => $this->string()->notNull()->unique(),
            'auth_key' => $this->string(32)->notNull(),
            'password_hash' => $this->string()->notNull(),
            'password_reset_token' => $this->string()->unique(),
            'email' => $this->string()->notNull()->unique(),
            'status' => $this->smallInteger()->notNull()->defaultValue(10),
            'created_at' => $this->integer()->notNull(),
            'updated_at' => $this->integer()->notNull(),
        ]);
    }

    public function down()
    {
        $this->dropTable('admin_user');
    }

运行命令：

yii migrate

生成 admin_user 表
接下来修改配置文件： backend/config/main.php，修改对user的配置为下面这样：

'user' => [
            'identityClass' => 'backend\models\AdminUser',
            'enableAutoLogin' => false,
            'identityCookie' => ['name' => '_identity-backend', 'httpOnly' => true],
        ],

在 backend/models/下创建 AdminUser.php 内容如下：

<?php
namespace backend\models;

use Yii;
use yii\base\NotSupportedException;
use yii\behaviors\TimestampBehavior;
use yii\db\ActiveRecord;
use yii\web\IdentityInterface;

/**
 * User model
 *
 * @property integer $id
 * @property string $username
 * @property string $password_hash
 * @property string $password_reset_token
 * @property string $email
 * @property string $auth_key
 * @property integer $status
 * @property integer $created_at
 * @property integer $updated_at
 * @property string $password write-only password
 */
class AdminUser extends ActiveRecord implements IdentityInterface
{
    const STATUS_DELETED = 0;
    const STATUS_ACTIVE = 10;


    /**
     * @inheritdoc
     */
    public static function tableName()
    {
        return 'admin_user';
    }

    /**
     * @inheritdoc
     */
    public function behaviors()
    {
        return [
            TimestampBehavior::className(),
        ];
    }

    /**
     * @inheritdoc
     */
    public function rules()
    {
        return [
            [['username', 'auth_key', 'password_hash', 'email', 'created_at', 'updated_at'], 'required'],
            [['status', 'created_at', 'updated_at'], 'integer'],
            [['username', 'auth_key'], 'string', 'max' => 32],
            [['password_hash', 'password_reset_token', 'email'], 'string', 'max' => 255],
            [['username','email'], 'unique'],
        ];
    }

    /**
     * @inheritdoc
     */
    public function attributeLabels()
    {
        return [
            'id' => 'ID',
            'username' => '用户名',
            'auth_key' => 'Auth Key',
            'password_hash' => 'Password Hash',
            'password_reset_token' => 'Password Reset Token',
            'email' => '邮箱',
            'status' => '状态',
            'created_at' => '创建时间',
            'updated_at' => '更新时间',
        ];
    }

    /**
     * @inheritdoc
     */
    public static function findIdentity($id)
    {
        return static::findOne(['id' => $id, 'status' => self::STATUS_ACTIVE]);
    }

    /**
     * @inheritdoc
     */
    public static function findIdentityByAccessToken($token, $type = null)
    {
        throw new NotSupportedException('"findIdentityByAccessToken" is not implemented.');
    }

    /**
     * Finds user by username
     *
     * @param string $username
     * @return static|null
     */
    public static function findByUsername($username)
    {
        return static::findOne(['username' => $username, 'status' => self::STATUS_ACTIVE]);
    }

    public static function findByEmail($email)
    {
        return static::findOne(['email' => $email]);
    }

    /**
     * Finds user by password reset token
     *
     * @param string $token password reset token
     * @return static|null
     */
    public static function findByPasswordResetToken($token)
    {
        if (!static::isPasswordResetTokenValid($token)) {
            return null;
        }

        return static::findOne([
            'password_reset_token' => $token,
            'status' => self::STATUS_ACTIVE,
        ]);
    }

    /**
     * Finds out if password reset token is valid
     *
     * @param string $token password reset token
     * @return boolean
     */
    public static function isPasswordResetTokenValid($token)
    {
        if (empty($token)) {
            return false;
        }

        $timestamp = (int) substr($token, strrpos($token, '_') + 1);
        $expire = Yii::$app->params['user.passwordResetTokenExpire'];
        return $timestamp + $expire >= time();
    }

    /**
     * @inheritdoc
     */
    public function getId()
    {
        return $this->getPrimaryKey();
    }

    /**
     * @inheritdoc
     */
    public function getAuthKey()
    {
        return $this->auth_key;
    }

    /**
     * @inheritdoc
     */
    public function validateAuthKey($authKey)
    {
        return $this->getAuthKey() === $authKey;
    }

    /**
     * Validates password
     *
     * @param string $password password to validate
     * @return boolean if password provided is valid for current user
     */
    public function validatePassword($password)
    {
        return Yii::$app->security->validatePassword($password, $this->password_hash);
    }

    /**
     * Generates password hash from password and sets it to the model
     *
     * @param string $password
     */
    public function setPassword($password)
    {
        $this->password_hash = Yii::$app->security->generatePasswordHash($password);
    }

    /**
     * Generates "remember me" authentication key
     */
    public function generateAuthKey()
    {
        $this->auth_key = Yii::$app->security->generateRandomString();
    }

    /**
     * Generates new password reset token
     */
    public function generatePasswordResetToken()
    {
        $this->password_reset_token = Yii::$app->security->generateRandomString() . '_' . time();
    }

    /**
     * Removes password reset token
     */
    public function removePasswordResetToken()
    {
        $this->password_reset_token = null;
    }
}

修改 backend/controllers/SiteController.php 主要是 use 部分

use Yii;
use yii\web\Controller;
use yii\filters\VerbFilter;
use yii\filters\AccessControl;
use backend\models\LoginForm;

主要是 使用后台自己的LoginForm
修改（没有则创建） backend/models/LoginForm.php

<?php
namespace backend\models;

use Yii;
use yii\base\Model;

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

    private $_user;


    /**
     * @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'],
        ];
    }

    /**
     * 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, '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
     */
    protected function getUser()
    {
        if ($this->_user === null) {
            $this->_user = AdminUser::findByUsername($this->username);
        }

        return $this->_user;
    }
}

主要注意代码：

$this->_user = AdminUser::findByUsername($this->username);

接下来就可以在 admin_user 表中手动创建一个账户，用于登录了（后台关闭注册功能，之后添加管理员也通过后台实现。）
添加 数据中的 password_hash 可以通过user表复制过来一个
到此，以后后台用户都是查询 admin_user表了。
接下来你可以后台创建针对admin_user 的CRUD模块。