如何动态显示消息react-router-dom

npm install react-router-dom

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

function App() {
  return (
    <Router>
      <Switch>
        <Route exact path="/" component={Home} />
        <Route path="/about" component={About} />
        <Route path="/contact" component={Contact} />
      </Switch>
    </Router>
  );
}

import { Link } from 'react-router-dom';

function Home() {
  return (
    <div>
      <h1>Home</h1>
      <Link to="/about">About</Link>
      <Link to="/contact">Contact</Link>
    </div>
  );
}

ReactDOM.render(<App />, document.getElementById('root'));