React-Hooks实现 componentWillUnmount使用 useEffect的第二个参数和return
销毁组件:importReact,{useState,useEffect}from'react';import{BrowserRouterasRouter,Link,Route}from'react-router-dom'functionIndex(){useEffect(()=>{console.log('Index页面的--来了---');return()=>{console.log('Ind