$assets = Yii::getPathOfAlias('ext').'/css';
//$baseUrl = Yii::app()->getAssetManager()->publish($assets);
$baseUrl = Yii::app()->assetManager->publish($assets); //extensions/css发布到assets的创建一个随机不冲突的文件夹下
Yii::app()->clientScript->registerCssFile($baseUrl.'/main.css');//引用assets下面的main.css

<?php
class AdminModule extends CWebModule
{
 private $_assetsUrl;

 public function getAssetsUrl()
 {
 if($this->_assetsUrl===null)
  $this->_assetsUrl=Yii::app()->getAssetManager()->publish(Yii::getPathOfAlias('application.modules.admin.assets'));
 return $this->_assetsUrl;
 }

 public function setAssetsUrl($value)
 {
 $this->_assetsUrl=$value;
 }
}

<link rel="stylesheet" type="text/css" href="<?php echo $this->module->assetsUrl; ?>/css/screen.css" rel="external nofollow" />

$baseJsUrl = Yii::app()->getAssetManager()->publish($baseJsPath, false, -1, YII_DEBUG);