EDIT

你把过程复杂化了。只要这样做:

index.js:

import React from 'react';
import ReactDom from 'react-dom';
import routes from './routes.js';
require('jquery');
import 'bootstrap/dist/css/bootstrap.min.css';
import 'bootstrap/dist/js/bootstrap.min.js';
import './css/main.css';

ReactDom.render(<routes />, document.getElementById('root'));

routes.js:

import React from 'react';
import { AppContainer } from 'react-hot-loader';
import { Router, Route, browserHistory, IndexRoute } from 'react-router';
import store from './store/store.js';
import { Provider } from 'react-redux';
import App from './containers/App.jsx';
import Products from './containers/shop/Products.jsx';
import Basket from './containers/shop/Basket.jsx';

const routes =
    <AppContainer>
        <Provider store={store}>
            <Router history={browserHistory}>
                <Route path="/" component={App}>
                    <IndexRoute component={Products} />
                    <Route path="/basket" component={Basket} />
                </Route>
            </Router>
        </Provider>
    </AppContainer>;

export default routes;

你可能会从某个文件返回object而不是只返回语句

错误的:

import React from 'react'
const About = () => {   return ( <div>About</div>   ) }
export default About

正确的:

import React from 'react'
const About = () => {   return 
<div>About</div>} 
export default About

我也得到了这个错误。

我用的是:

import BrowserRouter from 'react-router-dom';

费克斯是这样做的:

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

简而言之，不知何故发生了以下情况:

render() {
    return (
        <MyComponent /> // MyComponent is undefined.
    );
}

它不一定与某些不正确的输入或输出有关:

render() {
    // MyComponent may be undefined here, for example.
    const MyComponent = this.wizards[this.currentStep];

    return (
        <MyComponent />
    );
}

对我来说，我导入阿凡达就像 进口{ 《阿凡达》 }从'react-native-paper'; 在渲染时，我在TouchableOpacity中包装了Avatar元素，这导致了上述问题。移除TouchableOpacity后，一切正常。 <阿凡达。图像 ={{来源 uri:“……” }} 大小= {80} />

我所缺少的是我正在使用

import { Router, Route, browserHistory, IndexRoute } from 'react-router';

正确答案应该是:

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

当然你需要添加npm包react-router-dom:

npm install react-router-dom@next --save