react如何实现导航栏二级联动

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具体内容如下

效果图

js代码

import { Component } from "react";import './scroll.less' class Scroll extends Component {    constructor(...args) {        super(...args)        this.state = {            list: [                { id: 1, title: '列表1' },                { id: 2, title: '列表2' },                { id: 3, title: '列表3' },                { id: 4, title: '列表4' },                { id: 5, title: '列表5' },                { id: 6, title: '列表6' },                { id: 7, title: '列表7' },                { id: 8, title: '列表8' },                { id: 9, title: '列表9' },                { id: 10, title: '列表10' },                { id: 11, title: '列表11' },                { id: 12, title: '列表12' },                { id: 13, title: '列表13' },                { id: 14, title: '列表14' },                { id: 15, title: '列表15' },                { id: 16, title: '列表16' },                { id: 17, title: '列表17' },            ],            LeftList: [                { id: 1, title: '列表1', height: 800 },                { id: 2, title: '列表2', height: 600 },                { id: 3, title: '列表3', height: 500 },                { id: 4, title: '列表4', height: 900 },                { id: 5, title: '列表5', height: 450 },                { id: 6, title: '列表6', height: 300 },                { id: 7, title: '列表7', height: 900 },                { id: 8, title: '列表8', height: 1010 },                { id: 9, title: '列表9', height: 300 },                { id: 10, title: '列表10', height: 600 },                { id: 11, title: '列表11', height: 400 },                { id: 12, title: '列表12', height: 760 },                { id: 13, title: '列表13', height: 580 },                { id: 14, title: '列表14', height: 630 },                { id: 15, title: '列表15', height: 540 },                { id: 16, title: '列表16', height: 983 },                { id: 17, title: '列表17', height: 610 },            ],            curr: 0,//存储下标        }        // 默认添加一个 因为第一个的scrollTop值是0        this.LeftHeight = [0]        // 滚动的开关        this.Swich = true    }    // 渲染完成获取每一个列表距离顶部的距离    componentDidMount() {        // 定义为0 每次就可以循环加起来就是盒子距离顶部的距离        this.Height = 0        // 循环获取每一个的高        for (var i = 0; i < this.state.LeftList.length - 1; i++) {            this.Height += this.state.LeftList[i].height            // 将它添加到数组中            this.LeftHeight.push(this.Height)        }    }    //   点击左侧列表 点击获取下标    fnTab(Ind) {        // 点击的时候让右边的滚动事件为false        this.Swich = false        // 存储下标        this.setState({            curr: Ind        })        // 根据下标取出数组中对应下标的scrollTop值  就让右边的scrollTop为数组中取出的值        this.refs['rightItem'].scrollTop = this.LeftHeight[Ind];         // this.refs.scrollLeft.scrollTop = this.state.curr - 4 * 58.89    }    FnScroll() {        // 监听滚动        this.scrollTop = this.refs['rightItem'].scrollTop        // 这边用开关判断是否执行        if (this.Swich) {            // 存放下标            let num = 0            // 循环取出数组中的数值            for (var i = 0; i < this.LeftHeight.length - 1; i++) {                if (this.scrollTop >= this.LeftHeight[i]) {                    num = i                }            }            // 存储下标            this.setState({                curr: num            })        }        // 判断滚动的值和数组中的值相等 开关为true        if (this.scrollTop == this.LeftHeight[this.state.curr]) {            setTimeout(() => {                this.Swich = true;            });        }    }    render() {        return (            <div className='box'>                <div className='scroll'>                    <div className='scroll-right' ref='scrollLeft'>                        {this.state.list.map((item, index) => <div className='right-item' className={this.state.curr === index ? "active" : "right-item"} key={item.id} onClick={this.fnTab.bind(this, index)} >{item.title}</div>)}                    </div>                    <div className='scroll-left' ref='rightItem' onScroll={this.FnScroll.bind(this)}>                        {this.state.LeftList.map((item) => <div className='left-item' key={item.id} style={{ height: item.height }}><div className='item-title'>{item.title}</div></div>)}                    </div>                 </div>            </div>        )    }}export default Scroll

less代码

* {    margin: 0;    padding: 0;} .box {    width: 100vw;    height: 100vh;    background: red;     .scroll {        width: 100vw;        height: 100vh;        display: flex;         // 右边列表        .scroll-right {            width: 25vw;            background: aqua;            font-size: 28px;            height: 100vh;            overflow-y: auto;             .right-item {                width: 25vw;                height: 80px;                text-align: center;                line-height: 80px;                border-bottom: 1px solid #ccc;            }             .active {                height: 80px;                text-align: center;                line-height: 80px;                background: #0f0;            }        }         // 左边内容        .scroll-left {            width: 75vw;            height: 100vh;            overflow-y: auto;            //滚动的更加丝滑            scroll-behavior: smooth;             .left-item {                width: 75vw;                font-size: 30px;                text-align: center;                  .item-title {                    height: 30px;                    background: #ccc;                }            }        }    }}

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