lazyLoad

路由组件的懒加载

// 将组件引入改为使用lazy引入
import {lazy,Suspense} from 'react'

// import Topics from './Topics'
const Topics = lazy(()=>{import('./Topics')})

//修改注册路由，使用Suspense包裹
<Suspense fallback={<h1>Loading</h1>}>
	<Route path="/topics" component={Topics}/>
 </Suspense>