React 实现楼层效果

import React, { useEffect, useRef, useState } from 'react'
import { SideBar } from 'antd-mobile'
import "./css/louce.css"
import { useThrottleFn } from 'ahooks'
const Louce = () => {
    const items = [
        { key: '1', title: '第一项', text: [{ _id: "1", name: "商品1" }, { _id: "11", name: "商品12" }, { _id: "2", name: "商品13" }, { _id: "12", name: "商品14" }, { _id: "13", name: "商品15" }, { _id: "14", name: "商品16" }] },
        { key: '2', title: '第二项', text: [{ _id: "1", name: "商品1" }, { _id: "11", name: "商品12" }, { _id: "2", name: "商品13" }, { _id: "12", name: "商品14" }, { _id: "13", name: "商品15" }, { _id: "14", name: "商品16" }] },
        { key: '3', title: '第三项', text: [{ _id: "1", name: "商品1" }, { _id: "11", name: "商品12" }, { _id: "2", name: "商品13" }, { _id: "12", name: "商品14" }, { _id: "13", name: "商品15" }, { _id: "14", name: "商品16" }] },
        { key: '4', title: '第四项', text: [{ _id: "1", name: "商品1" }, { _id: "11", name: "商品12" }, { _id: "2", name: "商品13" }, { _id: "12", name: "商品14" }, { _id: "13", name: "商品15" }, { _id: "14", name: "商品16" }] },
    ]
    const [activeKey, setActiveKey] = useState('1')
    const { run: handleScroll } = useThrottleFn(
        () => {
            let currentKey = items[0].key
            for (const item of items) {
                const element = document.getElementById(`anchor-${item.key}`)
                if (!element) continue
                const rect = element.getBoundingClientRect()
                if (rect.top <= 0) {
                    currentKey = item.key
                } else {
                    break
                }
            }
            setActiveKey(currentKey)
        },
        {
            leading: true,
            trailing: true,
            wait: 100,
        }
    )
    const mainElementRef = useRef()
    useEffect(() => {
        const mainElement = mainElementRef.current
        if (!mainElement) return
        mainElement.addEventListener('scroll', handleScroll)
        return () => {
            mainElement.removeEventListener('scroll', handleScroll)
        }
    }, [])
    return (
        <div>
            <div className="container">
                <div className="side">
                    <SideBar
                        activeKey={activeKey}
                        onChange={key => {
                            document.getElementById(`anchor-${key}`)?.scrollIntoView()
                        }}
                    >
                        {items.map(item => (
                            <SideBar.Item key={item.key} title={item.title} />
                        ))}
                    </SideBar>
                </div>
                <div className="main" ref={mainElementRef}>
                    {items.map(item => (
                        <div key={item.key} className='mitem'>
                            <h2 id={`anchor-${item.key}`}>{item.title}</h2>
                            <div className='items'>
                                {item.text.map(itm => {
                                    return (
                                        <div>
                                            {itm.name}
                                        </div>
                                    )
                                })}
                            </div>
                        </div>
                    ))}
                </div>
            </div>
        </div>
    );
}
export default Louce;

.container {
    height: 100vh;
    background-color: #ffffff;
    display: flex;
    justify-content: flex-start;
    align-items: stretch;
  }
  .side {
    flex: none;
  }
  .main {
    flex: auto;
    padding: 0 24px 32px;
    overflow-y: scroll;
  }
  h2 {
    margin: 0;
    padding: 12px 0;
  }
  .mitem{
    height: 100vh;
  }
  .items{
    display: flex;
    flex-wrap: wrap;
  }
  .items>div{
    width: 100px;
    line-height: 50px;
  }