.orange{
  color: #f97910;
}

<template>
  <div class="productDetail" ref="content">
    <div class="tabbar">        
      <div @click.prevent="tabclick(index)" v-for="(item,index) in productTile" :key="index" :class="{orange:index==current}">{{item}}</div>    
    </div>
    <div id="0">...</div>
    <div id="1">...</div>
    <div id="2">...</div>
  </div>
<template>

tabclick(index){
  this.current=index;
  let anchorElement = document.getElementById(index);
  if(anchorElement) { anchorElement.scrollIntoView(); } 
},

.productDetail { 
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  overflow-y: scroll;
}

document.getElementsByClassName('productDetail')[0]; vue中同理于：this.$refs.content

methods:{
  handleScroll(el) {
    this.scrollTop = this.$refs.content.scrollTop;
    if (this.scrollTop >= 460) {
      this.current = 2
    } else if (this.scrollTop < 460 && this.scrollTop >= 360) {
      this.current = 1
    } else {
      this.current = 0
    }
   },
},
mounted() {
  //scoll滾動事件監(jiān)聽
  var pro_detail_page = document.getElementsByClassName('productDetail')[0];
  pro_detail_page.addEventListener('scroll', this.handleScroll);
},

// string.js slugify drops non ascii chars so we have to
// use a custom implementation here
// @ts-ignore
import { remove as removeDiacritics } from 'diacritics'
 
// eslint-disable-next-line no-control-regex
const rControl = /[\u0000-\u001f]/g
const rSpecial = /[\s~`!@#$%^&*()\-_+=[\]{}|\\;:"'<>,.?/]+/g
 
export = function slugify (str: string): string {
 return removeDiacritics(str)
 // Remove control characters
  .replace(rControl, '')
  // Replace special characters
  .replace(rSpecial, '-')
  // Remove continous separators
  .replace(/\-{2,}/g, '-')
  // Remove prefixing and trailing separtors
  .replace(/^\-+|\-+$/g, '')
  // ensure it doesn't start with a number (#121)
  .replace(/^(\d)/, '_$1')
  // lowercase
  .toLowerCase()
}