vue编程加入购物车（vuex实现简单的购物车功能）

<template>
    <li>
        <h1>vuex-shopCart</h1>
        <li class="shop-listbox">
            <shop-list />
        </li>
        <h2>已选商品</h2>
        <li class="shop-cartbox">
            <shop-cart />
        </li>
    </li>
</template>

<script>
import shoList from './shop-list'
import shopCart from './shop-cart'

export default {
  name: 'shop',
  components: {
      'shop-list' : shoList,
      'shop-cart' : shopCart
  }
}
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
</style>

<template>
    <li class="shop-list">
        <table>
            <tr class="shop-listtitle">
                <td>id</td>
                <td>名称</td>
                <td>价格</td>
                <td>操作</td>
            </tr>
            <tr v-for = "item in shopList" class="shop-listinfo" :key="item.id">
                <td>{{item.id}}</td>
                <td>{{item.name}}</td>
                <td>{{item.price}}</td>
                <td>
                    <button @click="addToCart(item)">加入购物车</button>
                </td>
            </tr>
        </table>
    </li>
</template>

<script>
import {mapGetters,mapActions} from "vuex";
export default {
    name : 'shopList',
    computed: {
        ...mapGetters({
                shopList:'getShopList',
            })
    },
    methods: {
        ...mapActions(['addToCart'])
    },
}
</script>

<template>
    <li class="shop-list">
        <table>
            <tr class="shop-listtitle">
                <td>id</td>
                <td>名称</td>
                <td>价格</td>
                <td>数量</td>
                <td>操作</td>
            </tr>
            <tr v-for="item in cartData" class="shop-listinfo" :key="item.id">
                <td>{{item.id}}</td>
                <td>{{item.name}}</td>
                <td>{{item.price}}</td>
                <td>{{item.num}}</td>
                <td><button class="shop-dele dele-btn" @click="deleteShop(item)">删除</button></td>
            </tr>
            <tr v-if="cartData.length <= 0">
                <td colspan="5">暂无数据</td>
            </tr>
            <tr>
                <td colspan="2">总数:{{totalNum}}</td>
                <td colspan="2">总价格:{{totalPrice}}</td>
                <td><button class="dele-cart dele-btn" @click="clearCart">清空购物车</button></td>
            </tr>
        </table>
    </li>
</template>

<script>
import {mapGetters,mapActions} from 'vuex'
export default {
    name : 'shopCart',
    data(){
        return{
            
        }
    },
    computed: {
        ...mapGetters({
            cartData:'addShopList',
            totalNum : 'totalNum',
            totalPrice:'totalPrice'
        })
    },
    methods: {
        ...mapActions({
            clearCart:'clearToCart',
            deleteShop:"deletToShop"
        })
    }
}
</script>

import Vue from "vue"
import Vuex from 'vuex'
import cart from './modules/cart'

Vue.use(Vuex)

export default new Vuex.Store({
    modules: {
        cart
    }
})

const state = {
    shop_list: [{
        id: 11,
        name: '鱼香肉丝',
        price : 12
    }, {
            id: 22,
            name: '宫保鸡丁',
            price : 14
        }, {
            id: 34,
            name: '土豆丝',
            price : 10
        }, {
            id: 47,
            name: '米饭',
            price : 2
        }, {
            id: 49,
            name: '蚂蚁上数',
            price : 13
        }, {
            id: 50,
            name: '腊肉炒蒜薹',
            price : 15
        }],
        add : []
}

const getters = {
    // 获取商品列表
    getShopList: state => state.shop_list,
    // 获取购物车列表
    addShopList: state => {
        // map()方法返回一个新数组，数组中的元素为原始数组元素调用函数处理后的值
        return state.add.map(({ id, num }) => {
            let product = state.shop_list.find(n => n.id == id)// find()方法返回通过测试(函数内判断)的数组的第一个元素的值，如果没有符合条件的元素返回undefined
            if (product) {//    如果存在该商品
                return {//  返回对象
                    ...product,
                    num
                }
            }
        })
    },
     // 获取总数量
     totalNum: (state, getters) => {
         let total = 0
         getters.addShopList.map(n => { 
             total += n.num
         })
         return total
    },
    // 计算总价格
    totalPrice: (state, getters) => { 
        let total = 0
        getters.addShopList.map(n => { 
            total += n.num * n.price
        })
        return total
    }
},

const actions = {
    // 加入购物车
    addToCart({ commit},product) { 
        commit('addCart', {
            id : product.id
        })
    },
    // 清空购物车
    clearToCart({ commit}) { 
        commit('clearCart')
    },
    // 删除单个物品
    deletToShop({ commit},product) { 
        commit('deletShop',product)
    }
}

const mutations = {
    // 加入购物车
    addCart(state, { id}){ 
        let record = state.add.find(n => n.id == id)
        if (!record) {//   如果购物车中不存在该商品
            state.add.push({//  追加商品
                id,
                num : 1
            })
        } else { // 如果商品已经加入购物车，则改变数量
            record.num++
        }
    },
    // 删除单个物品
    deletShop(state, product) { 
        state.add.forEach((item,i) => { 
            if (item.id == product.id) {//  如果找到该商品 
                state.add.splice(i,1)
            }
        })
    },
    // 清空购物车
    clearCart(state) { 
        state.add = []
    }
}

export default {
    state,
    getters,
    actions,
    mutations
}