yii2 如何开启session

yii2打开session （推荐学习：yii教程）

use  yiiwebSession; $session = Yii::$app->session;// check if a session is already openif ($session->isActive) ...// open a session$session->open();// close a session$session->close();// destroys all data registered to a session.$session->destroy();

设置session

$session = Yii::$app->session;$session->set('user_id', '1234');//OR$session['user_id'] = '1234';//OR$_SESSION['user_id'] = '1234';

读取session

$session = Yii::$app->session;$user_id = $session->get('user_id');//OR$user_id = $session['user_id'];//OR$user_id = isset($_SESSION['user_id']) ? $_SESSION['user_id'] : null;

销毁session

$session = Yii::$app->session;$session->remove('user_id');//ORunset($session['user_id']);//ORunset($_SESSION['user_id']);