安庆网络推广和竞价seo的五个步骤

先说使用场景，一次加载很多数据造成小程序卡顿的问题 ，找了好多都没有好的解决办法，要么太过复杂，然后研究了两天通过简单的办法实现，先根据数量把高度撑开，然后根据滚动位置渲染指定的数据就可以了， 性能简直不要太好。先看效果（实际业务效果要好于测试效果）。

DataManage.js  封装

function DataManage() {//**********************************************************数据let Data = {dataSource: [],//数据源heatData: [] //热数据(需要渲染的数据)}//**********************************************************配置let BaseConfig = { //基本配置信息(不需要覆盖的配置)triggerTime: 0, //滚动时间triggerTop: 0, //滚动top位置voidViewHeight: 0,//虚拟View高度pagingIndex: -1, //切换分页索引dataEnd: -1 //数据结束范围}let PagingConfig = { //分页配置(可改变) pageSize: 50, //分页大小cardHeight: 55, //卡片高度pagingBoundary: 20,//切换数据边界值(此值需要小于分页大小)topBoundary: 20, //数据上移边界callback: '',//回调方法debug: false //输出日志}let CallbackFn = null //回调方法//**********************************************************内部方法const refreshData = (viewData) => {//刷新数据Data.heatData = viewData.viewListCallbackFn(viewData)}const virtualPaging = () => {//虚拟分页if (Data.dataSource.length <= PagingConfig.pageSize) {//不分页处理refreshData({ viewList: Data.dataSource, voidViewHeight: BaseConfig.voidViewHeight, viewListTop: 0 })return;}let currentIndex = Math.floor(BaseConfig.triggerTop / PagingConfig.cardHeight)//根据位置计算当前索引值if (BaseConfig.pagingIndex == -1 || (currentIndex != BaseConfig.pagingIndex && Math.abs(currentIndex - BaseConfig.pagingIndex) >= PagingConfig.pagingBoundary)) {//数据范围let dataS = currentIndex - PagingConfig.topBoundary < 0 ? 0 : currentIndex - PagingConfig.topBoundary//起始位置let dataE = dataS + PagingConfig.pageSize//结束位置if (Math.abs(Data.dataSource.length - dataE) <= PagingConfig.pagingBoundary)//避免丢失最后的数据dataE = Data.dataSource.lengthif (dataE == BaseConfig.dataEnd)//避免总数据量只大于分页数造成的多一次渲染return;//返回后，此处会触发多次，因为下面的变量没有更新//刷新数据refreshData({viewList: Data.dataSource.slice(dataS, dataE),voidViewHeight: BaseConfig.voidViewHeight,viewListTop: dataS * PagingConfig.cardHeight})//保存此次分页位置 BaseConfig.dataEnd = dataEBaseConfig.pagingIndex = currentIndex//打印日志if (PagingConfig.debug)console.log("虚拟分页,位置索引->", currentIndex, "上次分页索引->", BaseConfig.pagingIndex, "数据范围[" + dataS + "-" + dataE + "]")}}//**********************************************************对外方法/*** 初始化*/const Init = (_pagingConfig, _data, _callback) => {PagingConfig = { ...PagingConfig, ..._pagingConfig }Data.dataSource = _dataCallbackFn = _callbackBaseConfig = {triggerTime: 0,triggerTop: 0,voidViewHeight: _data.length * PagingConfig.cardHeight,pagingIndex: -1,dataEnd: -1}virtualPaging()}/*** scroll-view 滚动事件*/const RollEvent = (e) => {if (Data.dataSource.length <= PagingConfig.pageSize)return;BaseConfig.triggerTime = new Date().getTime()BaseConfig.triggerTop = e.detail.scrollTopvirtualPaging()}return {Init, RollEvent}
}export {DataManage as dm
}

test1.js调用

import { dm } from "../../utils/DataManage"
const DM = dm()
Page({/*** 页面的初始数据*/data: {TestAllData: [],//为了测试位置 对齐voidViewHeight: 0,//虚拟列表高度 viewListTop: 0, //数据列表Top起始位置   viewList: [], //显示的数据},rollEvent(e) {//滚动事件DM.RollEvent(e)},/*** 生命周期函数--监听页面加载*/onLoad(options) {let DataSource = []for (var i = 0; i < 10000; i++) {DataSource.push({ sn: i, text: "第" + i + "个订单" })}this.setData({ TestAllData: DataSource })DM.Init({ debug: true }, DataSource, (data) => { this.setData(data)})}
})

 test1.wxml 布局

<view class="container"><view style="position: fixed; top: 0; background-color: blueviolet; width: 100%; height: 25px; z-index: 999; "><navigator url="/pages/order/order">订单</navigator></view><view style="margin-top:25px ; "><scroll-view enhanced scroll-y bindscroll="rollEvent" style="height: calc(100vh - 25px);"><view class="voidView" style="height:{{voidViewHeight}}px;"><view style=" height: 55px; align-content: center; color: greenyellow;" wx:for="{{TestAllData}}" wx:key="sn">{{item.sn }}</view></view><view class="dataView" style="top:{{viewListTop<0?0:viewListTop}}px"><view class="orderCard" wx:for="{{viewList}}" wx:key="sn">{{item.sn }} - {{item.text}}</view></view></scroll-view></view>
</view>

test1.wxss  样式

::-webkit-scrollbar {width: 0;height: 0;color: transparent;
}/* 占位元素 */
.voidView {position: absolute;width: 30px;background-image: url('http://192.168.1.8:808/images/back.png');
}/* 列表容器 */
.dataView {width: 100vw;padding-left: 30px;position: absolute;
}/* 订单卡片 */
.orderCard {height: 50px;background-color: coral;margin: 5px 5px 5px 5px;text-align: center;font-size: 24px;
}