Yii 2.0如何使用页面缓存方法示例

<?php namespace common/lib;use Yii;use yii/caching/Cache;use yii/di/Instance;use yii/web/Response;use yii/filters/PageCache as PCache;/*** 重写页面缓存，增加varByParam参数一列*/class PageCache extends PCache{ /** * 参数设置，默认无参数 * 用法：'varByParam' => Yii::$app->request->get('id') * @var string */ public $varByParam = ''; public function beforeAction($action) { if (!$this->enabled) {  return true; } $this->cache = Instance::ensure($this->cache, Cache::className()); if (is_array($this->dependency)) {  $this->dependency = Yii::createObject($this->dependency); } $properties = []; foreach (['cache', 'duration', 'dependency', 'variations'] as $name) {  $properties[$name] = $this->$name; } $id = $this->varyByRoute ? $action->getUniqueId().$this->varByParam : __CLASS__; $response = Yii::$app->getResponse(); ob_start(); ob_implicit_flush(false); if ($this->view->beginCache($id, $properties)) {  $response->on(Response::EVENT_AFTER_SEND, [$this, 'cacheResponse']);  return true; } else {  $data = $this->cache->get($this->calculateCacheKey());  if (is_array($data)) {  $this->restoreResponse($response, $data);  }  $response->content = ob_get_clean();  return false; } }} ?>

['class' => 'common/lib/PageCache',  'only' => ['view'],  'duration' => 0, //永不过期  'varByParam' => Yii::$app->request->get('id'),],