vue this.$emit传值触发两次

Question

<div class="tab" ref="tab">

  <div class="tab_content" ref="tabcontent">
      <div class="tab_item" v-for="(item,index) in menuList" ref="tabitem" :key="index" :class="clickIndex == index ? 'click-item' : ''" @click="itemClick(index)">
          {{item.name}}
      </div>
  </div>
  
  
  itemClick(index){
      this.clickIndex = index
      this.$emit("setMenu",index)
  }
  
  
   <scroller :menuList="menuList" @setMenu="setMenu"></scroller> 
   
   
    //menu点击
setMenu(index){
  console.log(index)
  let Id = this.menuList[index].id  //通过索引拿到相对应的id
  if (this.first != Id) {
    this.first = Id;
    this.listInfo = [] //清空
    this.pageNum = 1 //初始化
    this.NextPage = true; //初始化
    this.tip = false; //初始化
    this.loadMore(this.first)
  }
},