react的路由

<HashRouter>
  <Link exact to='/singer'>歌手</Link>
  <NavLink exact to='/recomment' activeClassName='hehe'>推荐</NavLink>
  <Switch>
    <Redirect from='/' to='/singer' exact />
    <Route path='/singer' component={组件}></Route>
    <Route path='/recomment' render={组件}></Route>
    <Route path='/singer' children={组件}></Route>
    <Route component={404}>
  </Switch>
</HashRouter>