componentDidMount声明周期版本

import React, { Component } from 'react'

interface Props {

}
interface State {

}

export default class index extends Component<Props, State> {
    state = {}

    render() {
        return (
            <div>

            </div>
        )
    }
    componentDidMount(){
        window.addEventListener('scroll', this.handleScroll);	
      }

      handleScroll(){
        console.log(window.scrollY)
      }
}

hooks版本

import React, { ReactElement, useEffect } from 'react'
import './index.css'

interface Props {

}

export default function Main({ }: Props): ReactElement {
    const [windowSize, setWindowSize] = React.useState({ width: 0, height: 0 })
 
    const windowChange = () => {
        const width = window.scrollX
        const height = window.scrollY
        setWindowSize({ width, height })
        console.log(height)
    }
 
    useEffect(() => {
        windowChange()
        window.addEventListener('scroll', windowChange)
 
        return () => {
            window.removeEventListener('scroll', windowChange)
        }
    }, [])


    return (
        <div className='maindiv'>
            Main
        </div>
    )

}