作用:
	能够更方便地给组件传递额外的属性
	
	<Route path={xx}  render={props=>{
	       return <组件 {...props}></组件> 
	 </Route>
	
	因为渲染的组件不是路由组件,所以需要传入props

代码示例:

import React from 'react';
import './App.css';
import {Switch,Route,Redirect} from 'react-router-dom'
import {Button} from 'antd'
import 'antd/dist/antd.css'
import {adminRoutes} from './routes/index'

function App() {
  return (
    <div className="App">
      <h1>app</h1>
      <Switch>
        {adminRoutes.map(route=>{
          return <Route  key={route.path} path={route.path} exact={route.exact} render={routeProps=>{
            return <route.component {...routeProps}></route.component> 
          }}></Route>
        })}
        <Redirect to='/404'></Redirect>
      </Switch>
    </div>
  );
}

export default App;