在React Router 4中嵌套路由(尝试在组件中包装路由)

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

const Home = () => (
  <div>
    <h2>Home</h2>
  </div>
);

const About = () => (
  <div>
    <h2>About</h2>
  </div>
);

const Topics = ({ match }) => (
  <div>
    <h2>Topics</h2>
    <ul>
      <li>
        <Link to={`${match.url}/topic1`}>Topic 1</Link>
      </li>
      <li>
        <Link to={`${match.url}/topic2`}>Topic 2</Link>
      </li>
    </ul>

    <Route path={`${match.path}/:topicId`} component={Topic} />
    <Route
      exact
      path={match.path}
      render={() => <h3>Please select a topic.</h3>}
    />
  </div>
);

const Topic = ({ match }) => (
  <div>
    <h3>{match.params.topicId}</h3>
  </div>
);

const App = () => (
  <Router>
    <div>
      <ul>
        <li>
          <Link to="/">Home</Link>
        </li>
        <li>
          <Link to="/about">About</Link>
        </li>
        <li>
          <Link to="/topics">Topics</Link>
        </li>
      </ul>

      <hr />

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

export default App;