學(xué)習(xí)react redux時(shí)引入react-thunk中間件報(bào)錯(cuò)
報(bào)錯(cuò)信息

項(xiàng)目是用create-react-app快速創(chuàng)建的

結(jié)構(gòu)目錄如下，各個(gè)文件代碼在下面貼出來(lái)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(
    <Provider store={store}>
        <App />
    </Provider>, 
    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 (
      <div className="App">
        App
      </div>
    );
  }
}

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) //這一塊不引入就不會(huì)報(bào)錯(cuò)，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;
}

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