vue列表单项展开收缩功能之this.$refs的详解

<li class="main-video"v-for="(item, index) of courseSubList" :key="item.id">
  <div class="audio-name">
    <div class="img-l">
      <span class="img-l-num">{{index+1}}</span>
      <span class="img-l-name">{{item.subName}}</span>
    </div>
    <div class="img-r" @click="showHide(index)" ref="arrow">
      <i class="iconfont">&#xe606;</i>
    </div>
  </div>
  <div class="audio-body" ref="child">
    <div class="body-l">
      <p class="body-l-num body-l-num-video">
        <i class="iconfont">&#xe62e;</i>
      </p>
      <span class="body-l-name">{{item.fileName}}</span>
    </div>
    <div class="body-r">
      <i class="iconfont" @click="deletCourseSub(item.id)">&#xe62c;</i>
    </div>
  </div>
</li>

data() {
	return {
		courseSubList: [], // 课程正文列表
	}
},
methods: {
  showHide(index) {
   if (this.$refs.child[index].style.display === 'none') {
    this.$refs.child[index].style.display = 'flex'
    this.$refs.arrow[index].style.transform = 'rotateX(0deg)'
   } else {
    this.$refs.child[index].style.display = 'none'
    this.$refs.arrow[index].style.transform = 'rotateX(180deg)'
   }
  },
  deletCourseSub(id) {
	  // 功能代码省略
  }
}