1、yii2系统登录
const EVENT_BEFORE_LOGIN = ‘beforeLogin‘; //登录前
const EVENT_AFTER_LOGIN = ‘afterLogin‘; //登录后
const EVENT_BEFORE_LOGOUT = ‘beforeLogout‘; //退出前
const EVENT_AFTER_LOGOUT = ‘afterLogout‘; //退出后原文：http://www.cnblogs.com/pcx105/p/6923212.html