一、项目截图

二、主要知识点

• vuex的使用
• json-server的使用

  json-server --watch index.json
  

三、需要注意的点

• json-server 安装成功，查看版本直接报错。安装默认版本埋下的一个坑，和node版本不匹配
• 作者直接安装vuex，默认安装也是版本不匹配，启动没报错，但是没法使用。作者是vue2版本，使用的vuex@3.1.1版本，安装的时候指定版本就好了

四、Main.js

import Vue from 'vue'
import App from './App.vue'
import store from './store'Vue.config.productionTip = falsenew Vue({store,render: h => h(App)
}).$mount('#app')

五、App.vue

<template><div class="app-container"><!-- Header 区域 --><cart-header></cart-header><!-- 商品 Item 项组件 --><cart-item v-for="item in list" :key="item.id" :item="item"></cart-item><!-- Foote 区域 --><cart-footer></cart-footer></div>
</template><script>
import CartHeader from '@/components/cart-header.vue'
import CartFooter from '@/components/cart-footer.vue'
import CartItem from '@/components/cart-item.vue'
import {mapState} from "vuex";export default {name: 'App',components: {CartHeader,CartFooter,CartItem},computed:{...mapState('cart',['list'])},created() {this.$store.dispatch('cart/getList')}
}
</script><style lang="less" scoped>
.app-container {padding: 50px 0;font-size: 14px;
}
</style>

六、components

cart-footer.vue

<template><div class="footer-container"><!-- 中间的合计 --><div><span>共 {{total}} 件商品，合计：</span><span class="price">￥{{ totalPrice}}</span></div><!-- 右侧结算按钮 --><button class="btn btn-success btn-settle">结算</button></div>
</template><script>
import {mapGetters} from 'vuex'export default {name: 'CartFooter',computed: {...mapGetters('cart', ['total', 'totalPrice'])}
}
</script><style lang="less" scoped>
.footer-container {background-color: white;height: 50px;border-top: 1px solid #f8f8f8;display: flex;justify-content: flex-end;align-items: center;padding: 0 10px;position: fixed;bottom: 0;left: 0;width: 100%;z-index: 999;
}.price {color: red;font-size: 13px;font-weight: bold;margin-right: 10px;
}.btn-settle {height: 30px;min-width: 80px;margin-right: 20px;border-radius: 20px;background: #42b983;border: none;color: white;
}
</style>

cart-header.vue

<template><div class="header-container">购物车案例</div>
</template><script>
export default {name: 'CartHeader'
}
</script><style lang="less" scoped>
.header-container {height: 50px;line-height: 50px;font-size: 16px;background-color: #42b983;text-align: center;color: white;position: fixed;top: 0;left: 0;width: 100%;z-index: 999;
}
</style>

cart-item.vue

<template><div class="goods-container"><!-- 左侧图片区域 --><div class="left"><img :src="item.thumb" class="avatar" alt=""></div><!-- 右侧商品区域 --><div class="right"><!-- 标题 --><div class="title">{{ item.name }}</div><div class="info"><!-- 单价 --><span class="price">{{ item.price }}</span><div class="btns"><!-- 按钮区域 --><button class="btn btn-light" @click="btnClick(-1)">-</button><span class="count">{{ item.count }}</span><button class="btn btn-light" @click="btnClick(1)">+</button></div></div></div></div>
</template><script>
export default {name: 'CartItem',props: {item: {type: Object,request: true}},methods: {btnClick(step) {const newCount = this.item.count + step;const id = this.item.id;if (newCount < 1) return;this.$store.dispatch('cart/updateCountAsync', {id,newCount})}}
}
</script><style lang="less" scoped>
.goods-container {display: flex;padding: 10px;+ .goods-container {border-top: 1px solid #f8f8f8;}.left {.avatar {width: 100px;height: 100px;}margin-right: 10px;}.right {display: flex;flex-direction: column;justify-content: space-between;flex: 1;.title {font-weight: bold;}.info {display: flex;justify-content: space-between;align-items: center;.price {color: red;font-weight: bold;}.btns {.count {display: inline-block;width: 30px;text-align: center;}}}}
}.custom-control-label::before,
.custom-control-label::after {top: 3.6rem;
}
</style>

七、store

index.js

import Vue from 'vue'
import Vuex from 'vuex'
import cart from "./modules/cart";Vue.use(Vuex)export default new Vuex.Store({modules: {cart}
})

modules/cart.js

import axios from "axios";export default {namespaced: true,state() {return {//购物车数据list: []}},mutations: {updateList(state, newList) {state.list = newList}},actions: {async getList(context) {const res = await axios.get("http://localhost:3000/cart")context.commit('updateList', res.data)},async updateCountAsync(context, obj) {await axios.patch(`http://localhost:3000/cart/${obj.id}`, {count: obj.newCount})//当前的this指向$storethis.dispatch('cart/getList')}},getters: {//商品总数total(state) {return state.list.reduce((sum, item) => sum + item.count, 0);},//商品总价totalPrice(state) {return state.list.reduce((sum, item) => sum + item.count * item.price, 0);}}
}