在react js中使用menuItem进行路由时，containerElement不起作用

npm install react-router-dom

import React from 'react';
import { BrowserRouter as Router, Route, Link } from 'react-router-dom';

// 定义两个组件作为路由的页面
const Home = () => <h1>Home Page</h1>;
const About = () => <h1>About Page</h1>;

// 在App组件中使用路由
const App = () => {
  return (
    <Router>
      <div>
        <ul>
          <li>
            <Link to="/">Home</Link>
          </li>
          <li>
            <Link to="/about">About</Link>
          </li>
        </ul>

        <hr />

        <Route exact path="/" component={Home} />
        <Route path="/about" component={About} />
      </div>
    </Router>
  );
};

export default App;