vue mounted中监听div的变化

vue mounted中监听div的变化

<div style="width:200px;height:30px;background: #0e90d2" id="list2">00</div>
<div @click="fun" id="list" style="width:200px;height:350px;background:blueviolet">{{$store.state.msg}}</div>

methods: {

  fun(){
    this.$store.dispatch('fun',this.checkedNames);

  },

mounted(){
  document.getElementById('list').addEventListener("DOMSubtreeModified", function(){
    var he=document.getElementById('list').offsetHeight;

    document.getElementById('list2').style.height=he+'px';
    console.log(he);
  }, false)
}