as shown above, I want to trigger an event when the user clicks X when the page is closed. Where should this event be written? Is it written and added in router.js? 
 for example: 
 {path: "message", 
 title:" message Center", 
 name: "message_index", 
 component: () = > import (" @ / views/message/message.vue") 
} 
 or is it added somewhere else? Ask the great god to guide ~ 
