反应。类型无效——期望为字符串

尝试得到react-router (v4.0.0)和react-hot loader (3.0.0-beta.6)很好地发挥，但在浏览器控制台得到以下错误:

Warning: React.createElement: type is invalid -- expected a string
(for built-in components) or a class/function (for composite
components) but got: undefined. You likely forgot to export your
component from the file it's defined in.

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';

const renderApp = (appRoutes) => {
    ReactDom.render(appRoutes, document.getElementById('root'));
};

renderApp( routes() );

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;

当前回答

我得到了完全相同的错误，做这个代替:

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

2020-11-12 06:51:32

其他回答

试试这个

npm i react-router-dom@next

在你的App.js中

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

const Home = () => <h1>Home</h1>

const App = () =>(
  <Router>
    <Route path="/" component={Home} />
  </Router>
)

export default App;

2017-05-09 11:25:16

当我在我的渲染/返回语句中有一个糟糕的引用时，这个问题出现在我身上。(指向不存在的类)。还要检查return语句代码中的错误引用。

2019-05-05 12:29:44

我得到了完全相同的错误，做这个代替:

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

2020-11-12 06:51:32

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

2022-08-11 14:08:41

这意味着您的导入/导出不正确。

检查新增的导入/导出。在我的例子中，我不必要地使用了大括号。当我去掉这些花括号时，问题就自动解决了。

import { OverlayTrigger } from 'react-bootstrap/OverlayTrigger';

2020-11-12 10:47:15

反应。类型无效——期望为字符串

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