Yii2：它是否有访问$ _REQUEST的抽象？

Does Yii2 have an abstraction for $_REQUEST? I don't seem to find it, so maybe there is a reason for not having it?

Maybe I have to figure it out manually by just using Yii::$app->request->get() and Yii::$app->request->post()?

Yii1 had it, in Yii2 it's gone.

You could just mimic old behavior with a adapted Request class though:

class Request extends \yii\web\Request {
    /**
     * for compatibility with yii1 request->getParam()
     */
    public function getParam($name, $defaultValue = NULL) {
        return isset($_GET[$name]) ? $_GET[$name] : (isset($_POST[$name]) ? $_POST[$name] : $defaultValue);
    }
} 

You need to override the request application component setting to use your own class then.