前言

网上购物车是顾客在进行网上购物时所必须使用的购物工具。它用来临时存储用户选择的商品，协助顾客从虚拟商场中选取商品、携带商品，并到虚拟的收银台结账。

1. 购物车作用

电商系统中很多产品功能都是从线下已存在的产品演化到线上的，购物车也是这样。在线下商超，我们经常会使用购物车，这个时候它承担的作用有：方便运输多件商品、方便选购大件商品、方便商品统一结算。搬到线上之后，购物车被赋予了更多能力：对于用户而言，它可以保存喜欢的商品、组合计算商品价格、商品比价、促销归类、降价提醒。对平台和商家而言，可以收集购物车数据、进行购物车营销、提高客单价。

一、商品购物车页面

<template>
  <view class="cart-container" v-if="cart.length !== 0">
    <!-- 收货地址组件 -->
    <my-address></my-address>

    <!-- 商品列表的标题区域 -->
    <view class="cart-title">
      <!-- 左侧的图标 -->
      <uni-icons type="shop" size="18"></uni-icons>
      <!-- 右侧的文本 -->
      <text class="cart-title-text">购物车</text>
    </view>

    <!-- 循环渲染购物车中的商品信息 -->
    <uni-swipe-action>
      <block v-for="(goods, i) in cart" :key="i">
        <uni-swipe-action-item :options="options" @click="swipeItemClickHandler(goods)">
          <my-goods :goods="goods" :show-radio="true" :show-num="true" @radio-change="radioChangeHandler" @num-change="numberChangeHandler"></my-goods>
        </uni-swipe-action-item>
      </block>
    </uni-swipe-action>

    <!-- 使用自定义的结算组件 -->
    <my-settle></my-settle>
  </view>

  <!-- 空白购物车的区域 -->
  <view class="empty-cart" v-else>
    <image src="/static/cart_empty@2x.png" class="empty-img"></image>
    <text class="tip-text">空空如也~</text>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'
  import { mapState, mapMutations } from 'vuex'

  export default {
    mixins: [badgeMix],
    computed: {
      ...mapState('m_cart', ['cart'])
    },
    data() {
      return {
        options: [{
          text: '删除',
          style: {
            backgroundColor: '#C00000'
          }
        }]
      };
    },
    methods: {
      ...mapMutations('m_cart', ['updateGoodsState', 'updateGoodsCount', 'removeGoodsById']),
      radioChangeHandler(e) {
        this.updateGoodsState(e)
      },
      numberChangeHandler(e) {
        this.updateGoodsCount(e)
      },
      swipeItemClickHandler(goods) {
        this.removeGoodsById(goods.goods_id)
      }
    }
  }
</script>

<style lang="scss">
  .cart-container {
    padding-bottom: 50px;
  }

  .cart-title {
    height: 40px;
    display: flex;
    align-items: center;
    padding-left: 5px;
    border-bottom: 1px solid #EFEFEF;

    .cart-title-text {
      font-size: 14px;
      margin-left: 10px;
    }
  }

  .empty-cart {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 150px;

    .empty-img {
      width: 90px;
      height: 90px;
    }

    .tip-text {
      font-size: 12px;
      color: gray;
      margin-top: 15px;
    }
  }
</style>

my-address组件

<template>
  <view>
    <!-- 选择收货地址的盒子 -->
    <view class="address-choose-box" v-if="JSON.stringify(address) === '{}'">
      <button type="primary" size="mini" class="btnChooseAddress" @click="chooseAddress">请选择收货地址+</button>
    </view>

    <!-- 渲染收货信息的盒子 -->
    <view class="address-info-box" v-else @click="chooseAddress">
      <view class="row1">
        <view class="row1-left">
          <view class="username">收货人：{{address.userName}}</view>
        </view>
        <view class="row1-right">
          <view class="phone">电话：{{address.telNumber}}</view>
          <uni-icons type="arrowright" size="16"></uni-icons>
        </view>
      </view>
      <view class="row2">
        <view class="row2-left">收货地址：</view>
        <view class="row2-right">{{addstr}}</view>
      </view>
    </view>

    <!-- 底部的边框线 -->
    <image src="/static/cart_border@2x.png" class="address-border"></image>
  </view>
</template>

<script>
  import { mapState, mapMutations, mapGetters } from 'vuex'

  export default {
    data() {
      return {
        // address: {}
      };
    },
    methods: {
      ...mapMutations('m_user', ['updateAddress']),
      async chooseAddress() {
        const [err, succ] = await uni.chooseAddress().catch(err => err)
        if (err === null && succ.errMsg === 'chooseAddress:ok') {
          // this.address = succ
          this.updateAddress(succ)
        }

        if (err && (err.errMsg === 'chooseAddress:fail auth deny' || err.errMsg === 'chooseAddress:fail authorize no response')) {
          // 通过调用这个方法，让用户重新授权
          this.reAuth()
        }
      },
      // 让用户重新授权
      async reAuth() {
        const [err2, confirmResult] = await uni.showModal({
          content: '检测到您没打开地址权限，是否去设置打开？',
          confirmText: '确认',
          cancelText: '取消'
        })

        if (err2) return

        console.log(confirmResult)

        if (confirmResult.cancel) return uni.$showMsg('您取消了地址授权！')
        if (confirmResult.confirm) return uni.openSetting({
          success: (settingResult) => {
            if (!settingResult.authSetting['scope.address']) return uni.$showMsg('您取消了授权！')
            if (settingResult.authSetting['scope.address']) return uni.$showMsg('授权成功！请选择地址')
          }
        })
      }
    },
    computed: {
      ...mapState('m_user', ['address']),
      ...mapGetters('m_user', ['addstr'])
    }
  }
</script>

<style lang="scss">
  .address-border {
    display: block;
    width: 100%;
    height: 5px;
  }

  .address-choose-box {
    height: 90px;
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .address-info-box {
    font-size: 12px;
    height: 90px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 0 5px;

    .row1 {
      display: flex;
      justify-content: space-between;

      .row1-right {
        display: flex;
        justify-content: space-between;
        align-items: center;
      }
    }

    .row2 {
      display: flex;
      align-items: center;
      margin-top: 10px;

      .row2-left {
        white-space: nowrap;
      }
    }
  }
</style>