这次给大家带来处理父组件方法更新到子组件无法渲染,处理父组件方法更新到子组件无法渲染的注意事项有哪些,下面就是实战案例,一起来看一下。
场景:
我实际用到的是这样的,我父组件引用子组件related,父组件调用获取页面详情的方法,更新了state值related,子组件根据该related来渲染相关新闻内容,但是页面打开的时候总是先加载子组件,子组件在渲染的时候还没有获取到更新之后的related值,即使在子组件中watch该值的变化依然不能渲染出来子组件的相关新闻内容。
我的解决办法:
父组件像子组件传值,当父组件执行了获取页面详情的方法之后,state值related更新,然后传给子组件,子组件再进行渲染,可以正常获取到。
父组件代码:
<template> <p id="newsDetails"> <mt-header title="详情"> <router-link to="/" slot="left"> <mt-button icon="back"></mt-button> </router-link> </mt-header> <p class="details clearfloat"> <h1 class="titleFont"> {{ title }} </h1> <p class="clearfloat sourceWrap"> <ul class="sourceFont"> <li v-if="(pubNews==true)"> <span class="source">{{pubName}}</span> </li> <li> <span class="authorName">{{authorName}}</span> <span class="time">{{createAt|formatTime}}</span> </li> </ul> <span v-if="(pubNews==true)" class='btnFollow' @click="follow">关注</span> </p> <p class="bodyFont clearfloat" id="bodyFont" ref="bodyFont" :class="{bodyHeight:contentStatus}"> <p v-html="content"></p> <p class="editor" v-if="editorName">责任编辑:{{editorName}}</p> </p> <p class="contentToggle" @click="contentStatus=!contentStatus" v-if="contentStatus">阅读全文</p> <Related :related="related"></Related> <!--重点是这里 父组件向子组件传值--> </p> </p> </template> 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); }, } }
子组件related.vue
<template> <p v-if="lists.length>0"> <p class="tagTitle"><span>相关新闻</span></p> <p class="listItem" v-if="(item.type=='little')" v-for="(item,index) in lists" :to="{name:'details',params:{id:item.id}}" :key="index" @click="browserDetection()"> <p class="listImg1"> <!--<img :src="{lazy==loaded?item.thumb[0]:lazy==loading?'../../assets/images/little_loading.png':lazy==error?'../../assets/images/little_loading.png'}" alt="" v-lazy="item.thumb[0]">--> <img :src="item.thumb[0]" alt="" v-lazy="item.thumb[0]"> </p> <p class='titleBox1'> <p class="listTitle">{{item.title}}</p> <p class="titleInfo"> <span class="openApp">打开唐人家</span> <span v-if="item.top==true" class="toTop">置顶</span> <!--<svg class="icon" aria-hidden="true"> <use xlink:href="#icon-dianzan" rel="external nofollow" ></use> </svg>--> <span class="like">阅读 {{item.read}}</span> <span class="time">{{item.createAt|formatTime}}</span> </p> </p> </p> </p> </template> <script> import {mapActions, mapState, mapGetters} from 'vuex' import moment from 'moment' export default{ data(){ return { lists: [], id:this.$route.params.id, } }, props:{ related:Array //重点是这里 }, created(){ moment.locale('zh-cn'); }, /*computed: { ...mapState({ related: state => state.newsDetails.related, }) },*/ filters:{ formatTime(time){ return moment(time).fromNow(); }, }, methods:{ }, watch: { related (val) { this.lists = val; }, '$route'(to,from){ this.id=this.$route.params.id } } } </script>
效果如图:
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