npm i better-scroll
import BScroll from 'better-scroll'
methods: {
  _initScroll () {
   this.menuScroll = new BScroll((this.$refs.menu), {
    click: true
    因为betterscroll默认会阻止点击事件。这里要设置一下
   })
   this.foodScroll = new BScroll((this.$refs.good), {
    probeType: 3
    用来获取滚动的距离
   })
   this.foodScroll.on('scroll', (pos) => {
    this.scrollY = Math.abs(Math.round(pos.y))
   })
  },

created () {
  this.$ajax.get('/api/data.json').then((res) => {
   this.goods = res.data.goods
   this.$nextTick(() => {
    this._initScroll()
    this.getGoodsHeight()
   })
  })
 },

getGoodsHeight () {
   let goodEle = this.$refs.good
   let height = 0
   this.listHeight.push(height)
   let foodList = goodEle.getElementsByClassName('goodsItemHook')
   for (let i = 0; i < foodList.length; i++) {
    let item = foodList[i]
    height += item.clientHeight
    this.listHeight.push(height)
   }
  },

this.foodScroll.on('scroll', (pos) => {
    this.scrollY = Math.abs(Math.round(pos.y))
   })

currentIndex () {
   for (let i = 0; i < this.listHeight.length; i++) {
    let height1 = this.listHeight[i]
    let height2 = this.listHeight[i + 1]
    if (!height2 || (this.scrollY < height2 && this.scrollY >= height1)) {
     return i
    }
   }
  }

:class="{'active': currentIndex == index}" 

handleGoodsItem (index) {
   let goodEle = this.$refs.good
   let foodList = goodEle.getElementsByClassName('goodsItemHook')
   let el = foodList[index]
   this.foodScroll.scrollToElement(el, 300)
  }