用vuex写了一个购物车H5页面的示例代码

# 全局安装 vue-cli

$ npm install --global vue-cli

# 创建一个基于 webpack 模板的新项目

$ vue init webpack my-project

# 安装依赖，走你

$ cd my-project

$ npm install

$ npm run dev

npm install --save vuex

import store from './store'

new Vue({

 el: '#app',

 store, //将store暴露出来

 components: { App },

 template: '<App/>'

})

import Vue from 'vue'

import Vuex from 'vuex'

import mutations from './mutations'

import actions from './actions'

import getters from './getters'

import shop from './modules/shop'

Vue.use(Vuex)

const state = {

 goods: [

  {

   id: '0',

   name: 'vivo-X20Plus屏幕指纹版',

   hint: '逆光也清晰，照亮你的美',

   price: 3596.00,

   num: 0,

   img: require('../assets/v.jpg')

  },

  {

   id: '1',

   name: '华为mate10Plus',

   hint: '真正的人工智能芯片',

   price: 4999.00,

   num: 0,

   img: require('../assets/h.jpeg')

  },

  {

   id: '2',

   name: '华为mate10Plus',

   hint: '真正的人工智能芯片',

   price: 4999.00,

   num: 0,

   img: require('../assets/v.jpg')

  }

 ],

 totalPrice: 0.00,

 totalNum: 0

}

export default new Vuex.Store({

 state,

 mutations,

 actions,

 getters,

 modules: {

  shop //shop模块

 }
})

// 使用常量，这是mutation-type.js文件

export const ADD_CART = 'ADD_CART'

export const REDUCE_CART = 'REDUCE_CART'

// 这是mutation.js文件

import {

 ADD_CART,

 REDUCE_CART

} from './mutation-types.js'

export default {

 [ADD_CART] (state, id) {

  state.goods[id].num++

  state.totalNum++

  state.totalPrice += state.goods[id].price

  // console.log(state.totalPrice)

 },

 [REDUCE_CART] (state, id) {

  if (state.goods[id].num > 0) {

   state.goods[id].num--

   state.totalNum--

   state.totalPrice -= state.goods[id].price

  }

 }

}

const getters = {

 goods_obj: state => state.goods,

 goods_length: state => state.goods.length

}
export default getters

<template>
 <div class="hello">
  <ul class="shop_container">
   <li v-for="item in $store.state.goods" :key="item.id" class="shop_container_li">

    <div class="shop_img">

     <img :src="item.img" alt="" width="100%" height="100%"/>

    </div>

    <div class="shop_detail">

     <p>{{item.name}}</p>

     <p>{{item.hint}}</p>

     <p>￥{{item.price}}</p>

     <p>

      <span class="shop_reduce" @click="reduce_num(item.id)">-</span>

      <span class="shop_num">{{item.num}}</span>

      <span class="shop_add" @click="add_num(item.id)">+</span>

     </p>

    </div>

   </li>

  </ul>

  <div class="foot">

   <div class="total_price">

    <span>合计：￥{{totalPrice}}</span>

   </div>

   <div class="total_num" :class="{payment: totalNum}">

    <span>去结账：{{totalNum}}</span>

   </div>

  </div>

 </div>

</template>

<script>

import {mapState, mapMutations, mapGetters} from 'vuex'

export default {

 name: 'HelloWorld',

 data () {

  return {

  }

 },

 created () {

  // console.log(this.goods)

  // console.log(this.goods_obj)

  // console.log(this.goods_length)

  // console.log(this.$store.state.shop) // 模块化 Vuex允许我们将 store 分割成模块（module）每个模块拥有自己的 state、mutation、action、getter、

 },

 computed: {

  ...mapState([

  // 获取state中的数据可以通过mapState辅助函数获取，也可以直接获取 例：this.$store.state.goods

   'goods', 'totalPrice', 'totalNum'

  ]),

  ...mapGetters([

   'goods_obj', 'goods_length'

  ])

 },

 methods: {

  ...mapMutations([

  // 获取mutation中的方法可以通过mapMutations 辅助函数获取，也可以直接获取。

   'ADD_CART'

   // 'REDUCE_CART'

  ]),

  reduce_num (id) {

   // this.REDUCE_CART(id)

   this.$store.commit('REDUCE_CART', id) //也可以直接获取

  },

  add_num (id) {

   this.ADD_CART(id) //通过mapMutations 辅助函数获取

  }

 }

}
</script>