React路由懒加载——lazy

1、lazy() 动态引入需要懒加载的组件

2、Suspense 来包裹需要懒加载的组件进行加载，设置fallback属性值实现加载中的效果

import { BrowserRouter as Router, Route, Switch } from 'react-router-dom';
import { Suspense, lazy } from 'react';
const Home = lazy(() => import('./Home'))
const About = lazy(() => import('./About'))
 
...
return (
  <Router>
    <Suspense fallback={<div>Loading...</div>}>
      <Switch>
        <Route exact path="/" component={Home}/>
        <Route path="/About" component={About}/>
        ...
      </Switch>
    </Suspense>
  </Router>

注：如果fallback={<Loading/>}中是组件，该Loading组件用import ... from '....'即可