父组件中vuex方法更新state子组件不能及时更新并渲染的完美解决方法

import { Toast } from 'mint-ui';
 import {mapState} from 'vuex'
 import Related from './Related.vue'
 import moment from 'moment';
 export default{
  name:"NewsDetails",
  components:{
   Related,
  },
  data(){
   return {
    id:this.$route.params.id,
    topicType:"news",
    contentStatus:false,
    curHeight:0,
    bodyHeight:5000,
    hotCommentScrollTop:0
   }
  },
  created(){
   this.id=this.$route.params.id;
   this.fetchData();
   moment.locale('zh-cn');
  },
  mounted(){
   setTimeout(()=>{
    this.contentToggle();
   },500)
  },
  watch: {
   '$route'(to,from){
    this.id=this.$route.params.id;
    this.fetchData();
   }
  },
  computed: {
   ...mapState({
    title: state => state.newsDetails.title,
    authorName: state => state.newsDetails.authorName,
    pubNews: state => state.newsDetails.pubNews,
    pubName: state => state.newsDetails.pubName,
    editorName: state => state.newsDetails.editorName,
    createAt: state => state.newsDetails.createAt,
    content: state => state.newsDetails.content,
    myFavourite: state => state.newsDetails.myFavourite,
    related: state => state.newsDetails.related,
   })
  },
  filters:{
   formatTime(time){
    return moment(time).fromNow();
   },
  },
  methods:{
   fetchData(){
    this.$store.dispatch('getDetails',this.id);
   },
   follow(){
    Toast('登录后进行关注');
    this.$router.push("/login");
   },
   contentToggle(){
    this.curHeight=this.$refs.bodyFont.offsetHeight;
    if(parseFloat(this.curHeight)>parseFloat(this.bodyHeight)){
     this.cOntentStatus=true;
    }else{
     this.cOntentStatus=false;
    }
//    this.hotCommentScrollTop=this.$refs.hotComment.height;
    console.log(this.hotCommentScrollTop);
   },
  }
 }