1 生命周期
var LIFECYCLE_HOOKS = ['beforeCreate', 'created', 'beforeMount', 'mounted',
'beforeUpdate', 'updated', 'beforeDestroy', 'destroyed',
'activated', 'deactivated', 'errorCaptured',
'serverPrefetch'];
、
2 特殊的生命周期:activated/deactivated (激活/停用)
使用keep-alive特殊组件才会触发