vue can not learn ---- activated trigger event

    methods:{
        handleScroll(){
            console.log(document.documentElement.scrollTop)
        }
    },
    activated(){
      window.addEventListener('scroll',this.handleScroll)
    }

activated, deactivated the life cycle of these two functions must be in use will be after the keep-alive component, otherwise not exist.

Is used in routing the outlet housing <keep-alive>