yii2 验证码详细代码 [ 2.0 版本 ]

yii2 验证码详细代码，有错误请指出
控制器 层 LoginController.php

<?php
namespace app\controllers;
use Yii;
use yii\web\Controller;
use app\models\Login;
use app\models\ContactForm;
class LoginController extends Controller
{
    public $enableCsrfValidation = false;
    public function actions()
    {
        return [
            'error' => [
                'class' => 'yii\web\ErrorAction',
            ],
            'captcha' => [
                'class' => 'yii\captcha\CaptchaAction',
                'fixedVerifyCode' => YII_ENV_TEST ? 'testme' : null,
            ],
        ];
    }
    public function actionLogin()
    {
        // 验证码
        $verify = new Login();

        return $this->render('login', [
            'verify' => $verify,
        ]);
    }
}

models 层 Login.php

<?php
namespace app\models;
use Yii;
use yii\base\Model;
class Login extends Model
{
    public $verifyCode;
    /**
     * @return array the validation rules.
     */
    public function rules()
    {
        return [
            // verifyCode needs to be entered correctly
            ['verifyCode', 'captcha'],
        ];
    }
    /**
     * @return array customized attribute labels
     */
    public function attributeLabels()
    {
        return [
            'verifyCode' => '验证码',
        ];
    }
}

view 层 login.php

<?php
use yii\bootstrap\ActiveForm;
use yii\captcha\Captcha;
?>
<div class="row">
    <div class="col-lg-5">
        <form action="">
        <?php $form = ActiveForm::begin(); ?>
        <?= $form->field($verify, 'verifyCode')->widget(Captcha::className(), [
            'template' => '<div class="row"><div class="col-lg-3">{image}</div><div class="col-lg-6">{input}</div></div>',
        ]) ?>
        <?php ActiveForm::end(); ?>
            // 这里面可以加你想要的任何表单
            <input type="submit" class="btn" value="提交"/>
        </form>
    </div>
</div>