import React from "react";
import { Link, BrowserRouter as Router, Route, Routes } from "react-router-dom";
import "./App.css";
import App from "./App";
const RouterPage = () => {
    return (
        <Router>
            <div>
                <nav>
                    <Link to="/">Home</Link>
                    <Link to="/posts">Posts</Link>
                    <Link to="/">About</Link>
                    <Link to="/contact">Contact</Link>
                </nav>
                <Routes>
                    <Route exact path="/" element={<App />}></Route>
                    <Route path="/post" element={<App />} />
                    <Route path="/about" element={<App />} />
                    <Route path="/contact" element={<App />} />
                </Routes>
            </div>
        </Router>
    );
};

你应该把Switch换成Routes

在安装react-router-dom v6.0.2后，我得到了这个错误。

用路由替换交换机解决了这个问题:

import {BrowserRouter as Router, Route, Routes} from "react-router-dom";

如果你正在使用react-router-dom的版本6，请使用这个

另外，请参考这里:https://reactrouter.com/docs/en/v6/upgrading/v5#:~:text=single%20route%20config%3A-，//%20This%20is%20a%20React%20Router%20v6%20app，%7D，-This%20step%20is

// This is a React Router v6 app
import {
  BrowserRouter,
  Routes,
  Route,
  Link,
  Outlet
} from "react-router-dom";

function App() {
  return (
    <BrowserRouter>
      <Routes>
        <Route path="/" element={<Home />} />
        <Route path="users" element={<Users />}>
          <Route path="me" element={<OwnUserProfile />} />
          <Route path=":id" element={<UserProfile />} />
        </Route>
      </Routes>
    </BrowserRouter>
  );
}

function Users() {
  return (
    <div>
      <nav>
        <Link to="me">My Profile</Link>
      </nav>

      <Outlet />
    </div>
  );
}

Switch组件没有从react-router-dom库中导出。要使用Switch组件，您需要从react-router库中导入它。它的代码看起来像这样:

import { Switch } from 'react-router';

在react-router-dom v6中，开关被路由替换。下面是配置react-router-dom v6的简单示例。

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

import Layout from './components/Layout';
import ProtectedRoute from './components/ProtectedRoute';
import LoginPage from './pages/LoginPage';
import WizardPage from './pages/WizardPage';
import RequestsPage from './pages/RequestsPage';

import './App.scss'

export class App extends React.Component {
    public render() {
        const sharedRouteProps = { exact: true, authenticationPath: '/login' };
        const wizardRouteProps = { ...sharedRouteProps, path: "/", component: WizardPage };
        const requestsRouteProps = { ...sharedRouteProps, path: "/requests", component: RequestsPage };

        return (
            <Layout>
              <Router>
                <Switch>
                    <Route exact path='/login' component={LoginPage} />
                    <ProtectedRoute {...wizardRouteProps} />
                    <ProtectedRoute {...requestsRouteProps} />
                </Switch>
              </Router>
            </Layout>
        );
    }
}

你的react-router-dom版本是什么?

"react-router": "^5.2.0",
"react-router-dom": "^5.2.0",

如果它大于1，那么你需要删除node-modules并使用npm install——save重新安装node-module。