UNIAPP实战项目笔记66 当前用户更改购物车商品数量的前端和后端交互

快来打我* 2024-03-22 15:14 73阅读 0赞

## UNIAPP实战项目笔记66 当前用户更改购物车商品数量的前端和后端交互 ##

### 思路 ###

> 前端改变数量的时候将数据发送到后端  
> 后端接收到数据后更改数据库中的数据

### 案例截图 ###

![在这里插入图片描述][7a08cc5a92b54486875466dac656d641.png]

### 代码 ###

#### 前端代码 cart.js ####

export default{
        
        state:{
        
            list:[
                    /* {
                        id:1,
                        name:"332经济法能聚聚会技能大赛 经济法能聚聚会技能大赛",
                        color:"颜色：嘿嘿嘿激活",
                        imgUrl:"../../static/logo.png",
                        pprice:"27",
                        num:1,
                        checked:false
                    },{
                        id:2,
                        name:"032经济法能聚聚会技能大赛 经济法能聚聚会技能大赛",
                        color:"颜色：嘿嘿嘿激活",
                        imgUrl:"../../static/logo.png",
                        pprice:"48",
                        num:6,
                        checked:false
                    } */
                ],
            selectedList:[]
            
        },
        getters:{
        
            // 判断是否 全选
            checkedAll(state){
        
                return state.list.length === state.selectedList.length;
            },
            // 合计 结算数量
            totalCount(state){
        
                let total = {
        
                    pprice:0,
                    num:0
                }
                state.list.forEach(v=>{
        
                    // 是否选中
                    if(state.selectedList.indexOf(v.id) > -1){
        
                        // 合计
                        total.pprice += v.pprice*v.num;
                        // 结算数量
                        total.num = state.selectedList.length;
                    }
                })            
                
                return total;
            }
        },
        mutations:{
        
            // 请求到数据赋值操作
            initGetData(state,list){
        
                state.list = list;
            },
            // 全选
            checkAll(state){
        
                state.selectedList = state.list.map(v=>{
        
                    v.checked = true;
                    return v.id;
                })
            },
            // 全不选
            unCheckAll(state){
        
                state.list.forEach(v=>{
        
                    v.checked = false;
                })
                state.selectedList = [];
            },
            // 单选
            selectedItem(state,index){
        
                let id = state.list[index].id;
                let i = state.selectedList.indexOf(id);
                // 如果selectList已经存在就代表他之前的选中状态,checked=false,并且在selectedList删除
                if (i>-1) {
        
                    state.list[index].checked = false;
                    return state.selectedList.splice(i,1);
                }
                // 如果之前没有选中,checked=true,把当前的id添加到selectedList
                state.list[index].checked = true;
                state.selectedList.push(id);
            },
            // 
            delGoods(state){
        
                state.list = state.list.filter(v=>{
        
                    return state.selectedList.indexOf(v.id) === -1;
                })
            },
            // 加入购物车
            addShopCart(state, goods){
        
                state.list.push(goods);
            }
        },
        actions:{
        
            checkedAllFn({
         commit,getters}){
        
                getters.checkedAll ? commit("unCheckAll") : commit("checkAll")
            },
            delGoodsFn({
         commit}){
        
                commit('delGoods');
                commit("unCheckAll");
                uni.showToast({
        
                    title:'删除成功',
                    icon:"none"
                })
            }
        }
    }

#### 前端代码 shopcart.vue ####

<template>
            <view class="shop-cart">
                <template v-if=" list.length > 0 ">
                        
                    
                    <uniNavBar
                        title="购物车"
                        :rightText=" isNavBar ? '完成' : '编辑'"
                        fixed="true"
                        statusBar="true"
                        @clickRight=" isNavBar = !isNavBar"
                    ></uniNavBar>
                    
                    
                    <view class="shop-item" v-for="(item,index) in list" :key="index">
                        <label for="" class="radio" @tap="selectedItem(index)">
                            <radio value="" color="#FF3333" :checked="item.checked" /> <text></text>
                        </label>
                        <image class="shop-img" :src="item.imgUrl" mode=""></image>
                        <view class="shop-text">
                            <view class="shop-name">
                                {
        {
        item.name}}
                            </view>
                            <view class="shop-color f-color">
                                {
        {
        item.color}}
                            </view>
                            <view class="shop-price">
                                <view class="">
                                    ￥{
        {
        item.pprice}}
                                </view>
                                <template v-if="!isNavBar">
                                    <view>x {
        {
        item.num}}</view>
                                </template>
                                <template v-else>
                                    <uniNumberBox
                                        :value="item.num"
                                        :min=1
                                        @change="changeNumber($event,index,item)"
                                    ></uniNumberBox>
                                </template>
                            </view>
                        </view>
                    </view>
                    
                    <view class="shop-foot">
                        <label for="" class="radio foot-radio" @tap='checkedAllFn'>
                            <radio value="" color="#FF3333" :checked="checkedAll"></radio><text>全选</text>
                        </label>
                        <template v-if="!isNavBar">
                            <view class="foot-total">
                                <view class="foot-count">
                                    合计：
                                    <text class="f-active-color">
                                        ￥{
        {
        totalCount.pprice}}
                                    </text>
                                </view>
                                <view class="foot-num" @tap="goConfirmOrder">
                                    结算({
        {
        totalCount.num}})
                                </view>
                            </view>
                        </template>
                        <template v-else>
                            <view class="foot-total">
                                <view class="foot-num" style="background-color: black;">
                                    移入收藏夹
                                </view>
                                <view class="foot-num" @tap="delGoodsFn">
                                    删除
                                </view>
                            </view>
                        </template>
                    </view>
                    
                </template>
                <template v-else>
                    <uniNavBar 
                        title="购物车"
                        fixed="true"
                        statusBar="true"
                    ></uniNavBar>
                    <view class="shop-else-list">
                        <text>囧~ 购物车还是空的~</text>
                    </view>
                </template>
                <Tabbar currentPage='shopcart'></Tabbar>
            </view>
        </template>
    
        <script>
            import $http from '@/common/api/request.js'
            import uniNavBar from '@/components/uni/uni-nav-bar/uni-nav-bar.vue'
            import uniNumberBox from '@/components/uni/uni-number-box/uni-number-box.vue'
            import Tabbar from '@/components/common/Tabbar.vue';//引入
            
            // 状态机引入
            import {
        mapState,mapActions,mapGetters,mapMutations} from 'vuex'
            export default {
        
                data() {
        
                    return {
        
                        isNavBar:false,
                    }
                },
                computed:{
        
                    // 状态机数据处理
                    ...mapState({
        
                        list:state=>state.cart.list
                    }),
                    ...mapGetters(['checkedAll','totalCount'])
                },
                components:{
        
                    uniNavBar,uniNumberBox,Tabbar
                },
                onShow() {
        
                  this.getData();  
                },
                methods: {
        
                    ...mapActions(['checkedAllFn','delGoodsFn']),
                    ...mapMutations(['selectedItem','initGetData']),
                    getData(){
        
                        $http.request({
        
                            url:'/selectCart',
                            method:"POST",
                            header:{
        
                                token:true
                            }
                        }).then((res)=>{
        
                            this.initGetData(res)
                        }).catch(()=>{
        
                            uni.showToast({
        
                            title:'请求失败',
                            icon:'none'
                            })
                        })
                    },
                    changeNumber(value,index,item){
        
                        if ( value == item.num ) return;
                        $http.request({
        
                            url:'/updateCart',
                            method:"POST",
                            header:{
        
                                token:true
                            },
                            data:{
        
                                goodsId:item.goods_id,
                                num:value
                            }
                        }).then((res)=>{
        
                            this.list[index].num = value;
                        }).catch(()=>{
        
                            uni.showToast({
        
                            title:'请求失败',
                            icon:'none'
                            })
                        })
                    },
                    // 进入确认订单
                    goConfirmOrder(){
        
                        uni.navigateTo({
        
                            url:'/pages/confirm-order/confirm-order'
                        })
                    }
                }
            }
        </script>
    
        <style lang="scss">
    
        .shop-list{
        
            padding-bottom: 100rpx;
        }
        .shop-else-list{
        
            position: absolute;
            left: 0;
            top: 0;
            right: 0;
            bottom: 0;
            background-color: #f7f7f7;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .shop-item{
        
            display: flex;
            padding: 20rpx;
            align-items: center;
            background-color: #f7f7f7;
            margin-bottom: 10rpx;
        }
        .shop-img{
        
            width: 200rpx;
            height: 200rpx;
        }
        .shop-text{
        
            flex: 1;
            padding-left: 20rpx;
        }
        .shop-color{
        
            font-size: 24rpx;
        }
        .shop-price{
        
            display: flex;
            justify-content: space-between;
        }
    
        .shop-foot{
        
            border-top: 2rpx solid #f7f7f7;
            background-color: #FFFFFF;
            position: fixed;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 100rpx;
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 120rpx;
        }
        .foot-radio{
        
            padding-left: 20rpx;
        }
        .foot-total{
        
            display: flex;
        }
        .foot-count{
        
            line-height: 100rpx;
            padding: 0 20rpx;
            font-size: 32rpx;
        }
        .foot-num{
        
            background-color: #49bdfb;
            color: #FFFFFF;
            padding: 0 60rpx;
            line-height: 100rpx;
        }
        </style>

#### 后端代码 index.js ####

#### 目录结构 ####

##### 前端目录结构 #####

*  manifest.json 配置文件： appid、logo…
 *  pages.json 配置文件： 导航、 tabbar、 路由
 *  
 *  main.js vue初始化入口文件
 *  App.vue 全局配置：样式、全局监视
 *  static 静态资源：图片、字体图标
 *  page 页面
    
     *  index
        
         *  index.vue
     *  list
        
         *  list.vue
     *  my
        
         *  my.vue
     *  my-config
        
         *  my-config.vue
     *  my-config
        
         *  my-config.vue
     *  my-add-path
        
         *  my-add-path.vue
     *  my-path-list
        
         *  my-path-list.vue
     *  search
        
         *  search.vue
     *  search-list
        
         *  search-list.vue
     *  shopcart
        
         *  shopcart.vue
     *  details
        
         *  details.vue
     *  my-order
        
         *  my-order.vue
     *  confirm-order
        
         *  confirm-order.vue
     *  payment
        
         *  payment.vue
     *  payment-success
        
         *  payment-success.vue
     *  login
        
         *  login.vue
     *  login-tel
        
         *  `login-tel.vue`
     *  login-code
        
         *  `login-code.vue`
 *  components 组件
    
     *  index
        
         *  Banner.vue
         *  Hot.vue
         *  Icons.vue
         *  indexSwiper.vue
         *  Recommend.vue
         *  Shop.vue
         *  `Tabbar.vue`
     *  common
        
         *  Card.vue
         *  Commondity.vue
         *  CommondityList.vue
         *  Line.vue
         *  ShopList.vue
     *  order
        
         *  order-list.vue
     *  uni
        
         *  uni-number-box
            
             *  uni-number-box.vue
         *  uni-icons
            
             *  uni-icons.vue
         *  uni-nav-bar
            
             *  uni-nav-bar.vue
         *  mpvue-citypicker
            
             *  mpvueCityPicker.vue
 *  common 公共文件：全局css文件 || 全局js文件
    
     *  api
        
         *  request.js
     *  common.css
     *  uni.css
 *  store vuex状态机文件
    
     *  modules
        
         *  cart.js
         *  path.js
         *  user.js
     *  index.js

[7a08cc5a92b54486875466dac656d641.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/18/41eb1608c8a943c99509c018fb761905.png