用react实现一个简单的scrollView组件

import { ReactNode, memo, useRef } from 'react'
import { ScrollViewWapper } from './style'
interface ScrollViewProps {
  children: ReactNode
}
const ScrollView = memo((
  {
    children
  }: ScrollViewProps
) => {
  const contentRef = useRef<HTMLDivElement>(null)
  return (
    <ScrollViewWapper>
      <div className='leftIcon'>左边</div>
      <div className='content-wapper-hidden'>
        <div className='render-content' ref={contentRef}>
          {children}
        </div>
      </div>
      <div className='rightIcon'>右边</div>
    </ScrollViewWapper>
  )
})
export default ScrollView

import { ReactNode, memo, useEffect, useRef, useState } from 'react'
import { ScrollViewWapper } from './style'
interface ScrollViewProps {
  children: ReactNode
}
const ScrollView = memo((
  {
    children
  }: ScrollViewProps
) => {
  const contentRef = useRef<HTMLDivElement>(null)
  const [maxoffset, setMaxOffset] = useState(0) // 两者最大的偏移量 可滚动距离
  const [currentOffsetIndex, setCurrentOffsetIndex] = useState(0) // 当前滚动元素的索引
  const handelIconClick = (isRoght: boolean) => {
  // 事件处理函数 
  }
  function getScrollOffset() {
    const scrollWidth = contentRef.current!.scrollWidth
    const clientWidth = contentRef.current!.clientWidth
    setMaxOffset(scrollWidth - clientWidth) // 计算最大偏移量
  }
  useEffect(() => {
    getScrollOffset()
  }, [])
  return (
    <ScrollViewWapper>
      <div className='leftIcon' onClick={() => handelIconClick(false)}>左边</div>
      <div className='content-wapper-hidden'>
        <div className='render-content' ref={contentRef}>
          {children}
        </div>
      </div>
      <div className='rightIcon' onClick={() => handelIconClick(true)}>右边</div>
    </ScrollViewWapper>
  )
})
export default ScrollView

import { ReactNode, memo, useEffect, useRef, useState } from 'react'
import { ScrollViewWapper } from './style'
interface ScrollViewProps {
  children: ReactNode
}
const ScrollView = memo((
  {
    children
  }: ScrollViewProps
) => {
  const contentRef = useRef<HTMLDivElement>(null)
  const [maxoffset, setMaxOffset] = useState(0) // 两者最大的偏移量 可滚动距离
  const [currentOffsetIndex, setCurrentOffsetIndex] = useState(0)
  const [isContinueScroll, setisContinueScroll] = useState(true)
  const handelIconClick = (isRight: boolean) => {
    const newIndex = isRight ? currentOffsetIndex + 1 : currentOffsetIndex - 1
    if (newIndex < 0 || (!isContinueScroll && isRight)) return // 边界处理
    const TabAllList = getAllElements('item', 'class') // 获取conntentRef 下面的 所有 item 子节点
    const TabItem = TabAllList[newIndex] as HTMLDivElement // 获取下一个 准备滚动元素
    const TabItemOffsetLeft = TabItem.offsetLeft
    contentRef.current!.style.transform = `translateX(${-TabItemOffsetLeft}px)`
    setisContinueScroll(maxoffset > TabItemOffsetLeft) // 是否能继续滚动 如果 你的 offsetLeft 都
    // 比我可滚动距离大了 ， 则肯定是不能滚动的
    setCurrentOffsetIndex(newIndex)
  }
  const getAllElements = (querySelectorName: string, type: 'id' | 'class' | 'el' = 'class') => {
    let seletorName = null
    if (type === 'id') { // 对选择器 做不同类型处理
      seletorName = `#${querySelectorName.replace(/\^#/, '')}`
    } else if (type == 'class') {
      seletorName = `.${querySelectorName.replace(/\^./, '')}`
    } else {
      seletorName = `${querySelectorName.replace(/\^(.|#)/, '')}`
    }
    return contentRef.current!.querySelectorAll(seletorName)
  }
  function getScrollOffset() {
    const scrollWidth = contentRef.current!.scrollWidth
    const clientWidth = contentRef.current!.clientWidth
    setMaxOffset(scrollWidth - clientWidth)
  }
  useEffect(() => {
    getScrollOffset()
  }, [])
  return (
    <ScrollViewWapper>
      <div className='leftIcon' onClick={() => handelIconClick(false)}>左边</div>
      <div className='content-wapper-hidden'>
        <div className='render-content' ref={contentRef}>
          {children}
        </div>
      </div>
      <div className='rightIcon' onClick={() => handelIconClick(true)}>右边</div>
    </ScrollViewWapper>
  )
})
export default ScrollView

import classNames from 'classnames';
import { memo, useState } from 'react';
import ScrollView from './components';
const Login = memo(() => {
  const [list, setList] = useState(['YYDS', '易烊千玺', '李易峰', '鸡哥', '古巨基', '罗志祥', '肖站', '彭于晏'])
  const [currentIndex, setCurrentIndex] = useState(0)
  return (
    <div id="danmu-container">
      <ScrollView>
        {
          list.map((item, index) => {
            return (
              <div className='item' key={item} onClick={() => setCurrentIndex(index)}>
                <div className={classNames('tab-item', currentIndex === index ? 'active' : '')}>{item}</div>
              </div>
            )
          })
        }
      </ScrollView>
    </div>
  )
})
export default Login