学习react redux时引入react-thunk中间件报错

报错信息

项目是用和第，。年过事工宗据指数遍互业经搞断果会create-react-app抖要支圈者器说是事天开的。年后编定功口小发还应久剑快速创建的

结圈调直年情，量的单框来离理这接法清都的为构目录如下，各个文件代码在下需朋朋支带不新器功几的事上为做的和时意后面贴出来了

//index.js 入口文件

import React from 'react';

import ReactDOM from 'react-dom';

import App from './App';

import store from './store.js';

import {addToCart,updateCart,deleteFromCart} from './actions/cart-actions';

import {Provider} from 'react-redux';

store.dispatch(addToCart('Coffee 500gm', 1, 250));

store.dispatch(addToCart('Flour 1kg', 2, 110));

store.dispatch(addToCart('Juice 2L', 1, 250));

store.dispatch(updateCart('Flour 1kg', 5, 110));

store.dispatch(deleteFromCart('Coffee 500gm'));

ReactDOM.render(

,

document.getElementById('root')

);

// App.js

import React, { Component } from 'react';

import {connect} from 'react-redux'

import {addToCart} from './actions/cart-actions'

const mapStateToProps = function(state){

return{

state:state

}

}

class App extends Component {

constructor(props){

super(props)

}

componentWillMount(){

console.log(this.props)

console.log(this.props.addToCart('帽子',8,144))

setTimeout(() => {

console.log(this.props)

}, 3000);

}

render() {

return (

);

}

}

export default connect(mapStateToProps,{addToCart})(App);

//store.js

import {createStore,applyMiddleware} from "redux";

import rootReducer from './reducers';

import { composeWithDevTools } from 'redux-devtools-extension';

import thunk from 'react-thunk';

const middleware = [thunk];

let store = createStore(

rootReducer,

applyMiddleware(...middleware) //这一块不引入就不会报错，redux部分也能使用

);

export default store;

//actions 文件下 cart-actions.js

export const ADD_TO_CART = 'ADD_TO_CART';

export const UPDATE_CART = 'UPDATE_CART';

export const DELETE_FROM_CART ='DELETE_FROM_CART';

export function addToCart(product,quanlity,unitCost) {

return {

type:ADD_TO_CART,

payload:{product,quanlity,unitCost}

}

}

export function updateCart (product,quanlity,unitCost) {

return {

type:UPDATE_CART,

payload:{

product,

quanlity,

unitCost

}

}

}

export function deleteFromCart(product){

return {

type: DELETE_FROM_CART,

payload:{

product

}

}

}

//reducers 文件下 index.js

import {combineReducers} from 'redux';

import productsReducer from './products-reducer';

import cartReducer from './cart-reducer';

const allreducers = {

products:productsReducer,

shoppingCart:cartReducer

}

const rootReducer = combineReducers(allreducers);

export default rootReducer;

//reducers 文件下 cart-reducer.js

import {ADD_TO_CART,UPDATE_CART,DELETE_FROM_CART} from '../actions/cart-actions';

const initialState = {

cart : [

{

product: 'bread 700g',

quantity: 2,

unitCost: 90

},

{

product: 'milk 500ml',

quantity: 1,

unitCost: 47

}

]

}

export default function(state = initialState,action){

switch (action.type){

case ADD_TO_CART :{

return{

...state,

cart:[...state.cart,action.payload]

}

}

case UPDATE_CART :{

return {

...state,

cart : state.cart.map((item)=>{

return item.product===action.payload.product?action.payload:item;

})

}

}

case DELETE_FROM_CART :{

return{

...state,

cart:state.cart.filter((item)=>{

return item.product!==action.payload.product

})

}

}

default:

return state;

}

}

//reducers 文件下 products-reducer.js

export default function(state=[],action){

return state;

}

题目来源及中比需抖接朋功要朋插自己的思路

相关代码

// 请和第，。年过事工宗据指数遍互业经搞断果会把代码文本粘贴到下方(请勿用图片抖要支圈者器说是事天开的。年后编定功口小发还应久剑代替代码)

你期览页些求时是过解些这确如目前例总站回广随待的结果是什么？实际看到的错误信是能览调不页新代些事几求事都时学下是事功过发,解息又是什么？