vue想在組件加載的時(shí)候通過mounted獲取computed中...mapState值的時(shí)候?yàn)閡nderfined，如何解決？

    computed:{
        ...mapState({
            user: state=>state.user,
            token:state=>state.token,
            teachers:state=>state.teachers
        })
    },
    mounted(){
        console.log('this.teachers',this.teachers)
        if(this.teachers.length == 0){
            this.getTeachers();
        }
    },