这是布局文件的一部分

<?php
/* this example is based on the advanced template
 * This file is located in 
 * backend/views/layouts/main.php 
 */

use yii\helpers\Html;

// here the asset is registered
use cinghie\adminlte\AdminLTEAsset;
AdminLTEAsset::register($this);

?>
<?php $this->beginPage() ?>
<!DOCTYPE html>
<html lang="<?= Yii::$app->language ?>">
<head>
    <meta charset="<?= Yii::$app->charset ?>">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <?= Html::csrfMetaTags() ?>
    <title><?= Html::encode($this->title) ?></title>
    <?php $this->head() ?>
</head>
   
 <body class="hold-transition skin-blue sidebar-mini">
    
<?php $this->beginBody() ?>

<?= $content ?>

<?php $this->endBody() ?>
            
</body>
</html>
<?php $this->endPage() ?>