yii2框架如何加载静态资源

<?php /**  * @link http://www.YIIframework.com/  * @copyright Copyright (c) 2008 Yii Software LLC  * @license http://www.yiiframework.com/license/  */   namespace appassets;   use yiiwebAssetBundle;   /**  * @author Qiang Xue <qiang.xue@gmail.com>  * @since 2.0  */ class AppAsset extends AssetBundle {     public $basePath = '@webroot';     public $baseUrl = '@web';       // 全局     public $css = [              ];       // 全局     public $js = [              ];       public $depends = [         // 'yiiwebYiiAsset',         // 'yiibootstrapBootstrapAsset',  // 注释掉禁用bootstrap     ];       // 这是设置所有js放置的位置      public $jsOptions = [           'position' =&gt; yiiwebView::POS_HEAD,         ];        //定义按需加载JS方法     public static function addJs($view, $jsfile) {          $view-&gt;registerJsFile(             $jsfile,              [                 AppAsset::className(),                  "depends" =&gt; "appassetsAppAsset"             ]         );      }        //定义按需加载css方法     public static function addCss($view, $cssfile) {          $view-&gt;registerCssFile(             $cssfile,              [                 AppAsset::className(),                  "depends" =&gt; "appassetsAppAsset"             ]         );      }    }

<?php   /* @var $this yiiwebView */ /* @var $content string */   use yiihelpersHtml; use yiibootstrapNav; use yiibootstrapNavBar; use yiiwidgetsBreadcrumbs; use appassetsAppAsset;   // 注册全局加载 AppAsset::register($this);   // 按需加载css AppAsset::addCss($this, Yii::$app->request-&gt;baseUrl."/css/site.css"); // 按需加载js AppAsset::addJs($this, Yii::$app-&gt;request-&gt;baseUrl."/js/respond.min.js");   ?&gt; <?php  $this->beginPage() ?&gt; nbsp;html&gt; language ?&gt;"&gt;      <meta>charset ?&gt;"&gt;     <meta>     <meta>     = Html::csrfMetaTags() ?&gt;     <title>= Html::encode($this-&gt;title) ?&gt;</title>     <?php  $this->head() ?&gt;   <?php  $this->beginBody() ?&gt;                = $content ?&gt;   <?php  $this->endBody() ?&gt;   <?php  $this->endPage() ?&gt;