reactjs - useSelector 无法从 'react-redux' 导出

Question

我有一个错误提示 Can't import 'UseSelector' from react-redux。我正在做的是一个名为 Getting started 的小项目

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import * as serviceWorker from './serviceWorker';
import { createStore, applyMiddleware, compose } from 'redux';
import rootReducer from './store/reducers/rootReducer'
import { Provider } from 'react-redux'
import thunk from 'redux-thunk'
import {createFirestoreInstance, reduxFirestore, getFirestore } from 'redux-firestore'
import { ReactReduxFirebaseProvider, getFirebase, reactReduxFirebase } from 'react-redux-firebase';
import firebase from 'firebase/app'
import fbConfig from './config/fbConfig'
import { useSelector } from 'react-redux'
import { isLoaded } from 'react-redux-firebase';



`
const store = createStore(rootReducer,
    compose(
        applyMiddleware(thunk.withExtraArgument({ getFirebase, getFirestore })),
        reduxFirestore(fbConfig),
        reactReduxFirebase(fbConfig, {attachAuthIsReady:true, firebase:'firebaseReducer'})    )
);


const rrfProps = {
    firebase,
    config: fbConfig,
    dispatch: store.dispatch,
    createFirestoreInstance,
    userProfile: 'users', // where profiles are stored in database
    presence: 'presence', // where list of online users is stored in database
    sessions: 'sessions'
}




function AuthIsLoaded({ children }) {
    const auth = useSelector(state => state.firebase.auth)
    if (!isLoaded(auth)) return <div>Loading Screen...</div>;
        return children
}

store.firebaseAuthIsReady.then(() => {
 
    
    
    ReactDOM.render(
        <Provider store={store}>
            <ReactReduxFirebaseProvider {...rrfProps}>
            <AuthIsLoaded>
                <App />
                </AuthIsLoaded>
            </ReactReduxFirebaseProvider>
        </Provider>,
        document.getElementById('root'));
    serviceWorker.unregister();
    
    
})

我试过重新启动 npm start，再次安装 react-redux，然后重新启动 npm start，运行 npm install 并关闭 Vscode，然后重新打开它。我试过了，我很困惑为什么它不起作用，但请帮我解决这个问题，谢谢 :D。

Answer 1

React Redux hooks were first added in v7.1.0所以如果你像你说的那样使用 React Redux v6.14.6，你就不能导入 useSelector 钩子(Hook)。

看起来你正在做一个类似教程的项目，所以我想你对包版本没有任何限制，你可以更新它而不会出现重大问题。请注意 React Redux 7.1 requires React 16.8.3 or later ，因此还要检查 package.json 文件中的 React 版本。

运行:

npm uninstall react react-redux
npm i react react-redux

然后检查你的 package.json 如果 dependencies 条目包含 "react-redux": "^7.2.1" 和 “ react ”:“^16.13.1”。