vue 长列表数据刷新的实现及思考

<div class="main">
    <div v-for="(dom) in longListEl" :key="dom.id" class="longList">
        <div :id="dom.id" class="contain">
            <div style="width: calc(100% - 20px);position: relative;">
                <div :style="{height:`${expectationCellHeight}px`}" v-for="(item,index) in dom.data" :key="item.id">
                    {{ item.title }}
                </div>
            </div>
        </div>
    </div>
</div>

export default {
    data() {
        return {
            longListData:[],
            expectationCellHeight:40,
            longListEl:[{id:'contain',data:[]},{id:'contain1',data:[]}],
            longListDataManages:[]
        };
    },
    mounted() {
        for(let index = 0;index < 250000;index ++){
            this.longListData.push({id:index,title:('我是第' + index + '个')})
        }
        this.$nextTick(()=>{
            this.longListEl.forEach((dom)=>{
                let containEl = document.getElementById(dom.id)
                if(containEl){
                    this.longListDataManages.push(new LongListDataManage(containEl,this.longListData,this.expectationCellHeight,(data)=>{
                        dom.data = data
                    }))
                }
            })
        })
    },
    methods: {
    },
};

function LongListDataManage(el,totalData,expectationCellHeight,refreshDataCallBack){
    this.el = el//需要操作的dom
    this.startIndex = 0//数据源的开始索引
    this.endIndex = 0//数据源的结束索引
    this.containElHeight = el ? el.offsetHeight : 0//可视区域高度
    this.totalData = totalData//全部数据源
    this.refreshDataCallBack = refreshDataCallBack//数据刷新回调
    this.expectationCellHeight = expectationCellHeight//预期的单元cell高度
    this.expectationCellFullScreenNum = 0//预期可视区域展示的单元条数
    this.expectationTotalHeight = 0//预期滑动的最大高度
    this.scrollTop = 0//当前滚动距离
    this.beginRefreshDataDistance = expectationCellHeight//滑动触发刷新数据最小距离，这里仅为一个单元格高度
    // 开始填充数据
    this.begin = function(){
        this.initData()
        this.getCurrentShowDatas()
        this.addListenerScroll()
    }
    // 初始化参数
    this.initData = function(){
        //总高度设定
        this.expectationTotalHeight = this.totalData.length * this.expectationCellHeight
        this.el.style.height = this.expectationTotalHeight + 'px'
        //数据源的结束索引设定（向上取整）
        this.endIndex = this.expectationCellFullScreenNum = Math.ceil((this.containElHeight / this.expectationCellHeight) + 0.1)
    }
    // 开始获取当前需要展示的区间
    this.getCurrentShowDatas = function(){
        //截取数据源开始跟结束节点之间的数据
        let currentData = this.totalData.slice(this.startIndex,this.endIndex)
        //给vue提供数据
        this.refreshDataCallBack(currentData)
    }
    // 监听滚动
    this.addListenerScroll = function(){
        //父节点
        let parentNode = this.el.parentNode
        //第一个子节点（改变其top值实现始终在父节点的可视区域内）
        let firstChild = this.el.firstChild
        let scrollingEvent = ()=>{
            let scrollTop = parentNode.scrollTop
            //滑动的距离超过规定的阀值或者滑动距离为0进行数据源重置
            if(Math.abs(scrollTop - this.scrollTop) >= this.beginRefreshDataDistance || scrollTop <= 0){
                //更改数据源区间索引
                this.startIndex = Math.ceil(scrollTop / this.expectationCellHeight)
                this.endIndex = this.startIndex + this.expectationCellFullScreenNum
                //上下平移可视区域展示dom，实现屏幕相对位置不变
                firstChild.style.top = scrollTop + 'px'
                //回传数据源
                this.getCurrentShowDatas()
                this.scrollTop = scrollTop
            }
        }
        //开始监听滚动
        parentNode.addEventListener("scroll", scrollingEvent)
    }
}