类型错误：未定义不是对象（评估“store.getState”）

Question

我正在关注Let's Build: Cryptocurrency Native Mobile App With React Native + Redux教程。

当我在 中创建我的商店时App.js，该应用程序运行良好

import { createStore, applyMiddleware, compose } from 'redux';
import devTools from 'remote-redux-devtools';
import React, { Component } from 'react';
import { Platform, View } from 'react-native';
import { Provider } from 'react-redux';
import promise from 'redux-promise';
import thunk from 'redux-thunk';
import logger from 'redux-logger';

import { Header, CryptoContainer } from './src/components';
import rootReducer from './src/reducers';    

const middleware = applyMiddleware(thunk, promise, logger);

const Store = createStore(rootReducer, compose(middleware, devTools({
  name: Platform.OS,
  hostname: 'localhost',
  port: 5678
}), ));

export default class App extends Component {
  render() {
    return (
      <Provider store={Store}>
        <View>
          <Header />
          <CryptoContainer />
        </View>
      </Provider>
    );
  }
}

但是当我将存储逻辑移动到一个新文件时./src/Store.js，

import { Platform } from 'react-native';    
import { createStore, applyMiddleware, compose } from 'redux';
import devTools from 'remote-redux-devtools';
import promise from 'redux-promise';
import thunk from 'redux-thunk';
import logger from 'redux-logger';

import rootReducer from './reducers';

const middleware = applyMiddleware(thunk, promise, logger);

const Store = createStore(rootReducer,compose(middleware,devTools({
            name: Platform.OS,
            hostname: 'localhost',
            port: 5678
        }),
    )
);

export default Store;

并用它在App.js像

import React, { Component } from 'react';
import { View } from 'react-native';
import { Provider } from 'react-redux';

import { Header, CryptoContainer } from './src/components';
import { Store } from './src/Store';

export default class App extends Component {
  render() {
    return (
      <Provider store={Store}>
        <View>
          <Header />
          <CryptoContainer />
        </View>
      </Provider>
    );
  }
}

我得到

类型错误：未定义不是对象（评估“store.getState”）

expo start导入时是什么导致我的构建 ( ) 失败Store.js？

Answer 1

看来导入语句不对。它应该是：

import Store from './src/Store';

Answer 2

如果你要导入一个single named export
例如你已经完成的地方，export const MyComponent = () => {}你会像这样导入它
import { MyComponent } from "./MyComponent"

如果你要导入一个default export
例如你已经完成的地方，const MyComponent = () => {} export default MyComponent你会像这样导入它
import MyDefaultComponent from "./MyDefaultExport"