反应路由器不渲染路由

Question

尝试使用 React Router 时，我不断收到错误消息，指出我的 Route 必须在 Router 内，即使它已经在了。我已经尝试再次运行 npm install，并删除和读取 react router npm 包。错误信息是

Invariant failed: You should not use <Route> outside a <Router>

index.js

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import reportWebVitals from './reportWebVitals';
import { BrowserRouter as Router } from 'react-router-dom';

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

app.js

import logo from './logo.svg';
import './App.css';
import Main from './Components/Main/main';
import {BrowserRouter, Route,Link } from 'react-router-dom';

function App() {
  return (

    <div className="App">
      
     
      <Route  exact path='/'>
        <Main />
      </Route>
     
 
    </div>
    
  );
}

export default App;

main.js

export default function Main(props) {
    const [anim,setAnim] = useState(false);

    return (
        
        <MainSection>
          
        
              
        </MainSection>
     
    )
}