使用Taro实现小程序商城的购物车功能模块的详细解析

# 使用 npm 安装 CLI
$ npm install -g @tarojs/cli
# OR 使用 yarn 安装 CLI
$ yarn global add @tarojs/cli
# OR 安装了 cnpm，使用 cnpm 安装 CLI
$ cnpm install -g @tarojs/cli

使用命令创建模板项目
 $ taro init myApp
npm 5.2+ 也可在不全局安装的情况下使用 npx 创建模板项目
$ npx @tarojs/cli init myApp

# 使用 yarn 安装依赖
$ yarn
# OR 使用 cnpm 安装依赖
$ cnpm install
# OR 使用 npm 安装依赖
$ npm install

# yarn
$ yarn dev:weapp
$ yarn build:weapp
# npm script
$ npm run dev:weapp
$ npm run build:weapp
# 仅限全局安装
$ taro build --type weapp --watch
$ taro build --type weapp
# npx 用户也可以使用
$ npx taro build --type weapp --watch
$ npx taro build --type weapp

import { View, Icon, Navigator, Image, Text, } from '@tarojs/components'
import Taro from '@tarojs/taro'
import './cart.less'
 
class Cart extends Taro.Component {
 config = {
 navigationBarTitleText: '购物车'
 }
 
 state = {
 carts: [
 {
 id: 1,
 title: '好喝⾼颜值MEOW莫斯卡托⽓泡葡萄酒甜型⾹槟少⼥粉猫起泡酒(v1)',
 image:
  'https://tva1.sinaimg.cn/large/00831rSTgy1gczok56tkzj30m80m8qe4.jpg',
 num: 3,
 price: '88.00',
 selected: true
 },
 {
 id: 2,
 title: '好喝⾼颜值MEOW莫斯卡托⽓泡葡萄酒甜型⾹槟少⼥粉猫起泡酒(v2)',
 image:
  'https://tva1.sinaimg.cn/large/00831rSTgy1gczok56tkzj30m80m8qe4.jpg',
 num: 1,
 price: '188.00',
 selected: true
 },
 {
 id: 3,
 title: '好喝⾼颜值MEOW莫斯卡托⽓泡葡萄酒甜型⾹槟少⼥粉猫起泡酒(v3)',
 image:
  'https://tva1.sinaimg.cn/large/00831rSTgy1gczok56tkzj30m80m8qe4.jpg',
 num: 2,
 price: '288.00',
 selected: false
 },
 {
 id: 4,
 title: '好喝⾼颜值MEOW莫斯卡托⽓泡葡萄酒甜型⾹槟少⼥粉猫起泡酒(v4)',
 image:
  'https://tva1.sinaimg.cn/large/00831rSTgy1gczok56tkzj30m80m8qe4.jpg',
 num: 2,
 price: '388.00',
 selected: false
 }
 ], // 购物车列表
 hascheckList: [], 
 totalPrice: 0, // 总价，初始为0
 selectAllStatus: true // 全选状态，默认全选
 }
 
 componentDidShow() {
 const cart = [
 
 ]
 this.setState({
 carts: cart
 })
 this.getTotalPrice();
 }
 
 /**
 * 计算总价
 */
 getTotalPrice() {
 let carts = this.state.carts // 获取购物车列表
 let total = 0
 for (let i = 0; i < carts.length; i++) {
 // 循环列表得到每个数据
 if (carts[i].selected) {
 // 判断选中才会计算价格
 total += carts[i].num * carts[i].price // 所有价格加起来
 }
 }
 this.setState({
 // 最后赋值到data中渲染到页面
 carts: carts,
 totalPrice: total.toFixed(2)
 })
 }
 
 
 /**
 * 绑定加数量事件
 */
 addCount(e) {
 const index = e.currentTarget.dataset.index
 let carts = this.state.carts
 let num = carts[index].num
 num = num + 1
 carts[index].num = num
 this.setState({
 carts: carts
 })
 this.getTotalPrice()
 }
 
 /**
 * 绑定减数量事件
 */
 minusCount(e) {
 const index = e.currentTarget.dataset.index
 let carts = this.state.carts
 let num = carts[index].num
 if (num <= 1) {
 return false
 }
 num = num - 1
 carts[index].num = num
 this.setState({
 carts: carts
 })
 this.getTotalPrice()
 }
 
 /**
 * 删除购物车当前商品
 */
 deleteList(e) {
 const index = e.currentTarget.dataset.index
 let carts = this.state.carts
 carts.splice(index, 1)
 this.setState({
 carts: carts
 })
 if (!carts.length) {
 this.setState({
 hasList: false
 })
 } else {
 this.getTotalPrice()
 }
 }
 
 /**
 * 当前商品选中事件
 */
 selectList(id,e) {
 const index = e.currentTarget.dataset.index
 let carts = this.state.carts
 // const selected = carts[index].selected
 // carts[index].selected = !selected
 
 carts.forEach(item => {
 if (id == item.id) {
 item.selected = !item.selected
 }
 })
 // const checkall = this.data.selectAllStatus === true &#63; false : false
 this.setState({
 carts: carts, 
 // selectAllStatus: false
 })
 
 const selectAllStatus = carts.every(item => item.selected)
 this.setState({
 selectAllStatus: selectAllStatus
 })
 this.getTotalPrice()
 }
 
 /**
 * 购物车全选事件
 */
 selectAll(e) {
 let selectAllStatus = this.state.selectAllStatus
 selectAllStatus = !selectAllStatus
 let carts = this.state.carts
 
 for (let i = 0; i < carts.length; i++) {
 carts[i].selected = selectAllStatus
 }
 this.setState({
 selectAllStatus: selectAllStatus,
 carts: carts
 })
 this.getTotalPrice()
 }
 
 // 结算
 closeFun() {
 let list = []
 let listTotal = []
 this.state.carts.map((v, k) => {
 console.log('购物车数据', v)
 if (v.select) {
 list.push(v)
 } else {
 listTotal.push(v)
 }
 })
 }
 
 render() {
 const { carts, selectAllStatus, totalPrice, hasList } = this.state;
 let count = 0;
 carts.map(it => {
 if(it.selected === true) {
 count++;
 }
 })
 return (
 <View className="main">
 {carts.length > 0 &#63; (
  <View>
  <View className="cart-box">
  {carts.map((item, index) => {
  return (
   <View className="cart-list" key={index}>
   {item.selected &#63; (
   <Icon
   type="success"
   color="#b30000"
   data-index={index}
   className="cart-pro-select"
   onClick={this.selectList.bind(this,item.id)}
   ></Icon>
   ) : (
   <Icon
   type="circle"
   className="cart-pro-select"
   data-index={index}
   onClick={this.selectList.bind(this,item.id)}
   ></Icon>
   )}
   <Navigator url={'../details/details&#63;id=' + item.id}>
   <Image className="cart-thumb" src={item.image}></Image>
   </Navigator>
   <Text className="cart-pro-name">{item.title}</Text>
   <Text className="cart-pro-price">{'￥' + item.price}</Text>
   <View className="cart-count-box">
   <Text
   className="cart-count-down"
   onClick={this.minusCount}
   data-index={index}
   >
   -
   </Text>
   <Text className="cart-count-num">{item.num}</Text>
   <Text
   className="cart-count-add"
   onClick={this.addCount}
   data-index={index}
   >
   +
   </Text>
   </View>
   <Text
   className="cart-del"
   onClick={this.deleteList}
   data-index={index}
   >
   删除
   </Text>
   </View>
  )
  })}
  </View>
  <View className="cart-footer">
  {selectAllStatus &#63; (
  <Icon
   type="success_circle"
   color="#b30000"
   className="total-select"
   onClick={this.selectAll}
  ></Icon>
  ) : (
  <Icon
   type="circle"
   color="#b30000"
   className="total-select"
   onClick={this.selectAll}
  ></Icon>
  )}
  <Navigator url="../orders/orders">
  <View className="order-icon"></View>
  </Navigator>
  <Text >{count> 0&#63; `已选(${count})`: '全选'}</Text>
  <Text className="cart-toatl-price">{'合计￥' + totalPrice}</Text>
  <Text className="pay" onClick={this.closeFun} data-index={index}>
  立即下单
  </Text>
  </View>
  </View>
 ) : (
  <View>
  <View className="cart-no-data">购物车是空的哦~</View>
  </View>
 )}
 </View>
 )
 }
} 
 
export default Cart

/* pages/cart/cart.wxss */
 
.cart-box{
 padding-bottom: 100px;
 margin-bottom: 10px
}
.cart-list{
 position: relative;
 padding: 20px 20px 20px 285px;
 height: 185px;
 border-bottom: 1px solid #e9e9e9;
}
.cart-list .cart-pro-select{
 position: absolute;
 left: 20px;
 top: 90px;
 width: 45px;
 height: 45px;
}
 
.cart-list .cart-thumb{
 position: absolute;
 top: 20px;
 left: 85px;
 width: 185px;
 height: 185px;
 border-radius:5px;
 box-shadow:5px 2px 6px #000
}
.cart-list .cart-pro-name{
 display: inline-block;
 // width: 500px;
 height: 105px;
 line-height: 50px;
 overflow: hidden;
 font-family: Microsoft Yahei, Cochin, Georgia, Times, 'Times New Roman', serif;
 font-size:28px;
 margin-right: 15px
}
 
.cart-list .cart-pro-price{
 display: inline-block;
 font-size:30px;
 color: #b30000;
 height: 105px;
 line-height: 50px;
}
.cart-list .cart-count-box{
 position: absolute;
 left: 420px;
 bottom: 20px;
 width: 250px;
 height: 80px;
}
.cart-list .cart-count-box text{
 display: inline-block;
 line-height: 80px;
 text-align: center;
}
.cart-count-down,.cart-count-add{
 font-size: 32px;
 width: 60px;
 height: 80px;
 font-family: Microsoft Yahei, Cochin, Georgia, Times, 'Times New Roman', serif;
 border: silver solid 1px;
 border-radius: 10px;
}
.cart-count-num{
 width: 80px;
 font-size: 32px;
 height: 80px;
 border-radius: 10px;
 border: silver solid 1px;
 margin-left: 1px;
 margin-right: 1px;
}
.cart-del{
 position: absolute;
 right: 15px;
 bottom: 20px;
 width: 80px;
 height: 80px;
 line-height: 80px;
 text-align: center;
 font-family: Arial,Helvetica,sans-serif;
 font-size:30px;
 color: #b30000;
 text-shadow: black;
}
.cart-footer{
 position: fixed;
 bottom: 0;
 left: 0;
 width: 100%;
 height: 90px;
 line-height: 90px;
 padding:0 100px 0 80px;
 box-sizing: border-box;
 background: #bfbfbf;
 color: #4d4d4d;
 font-family: Microsoft Yahei, Cochin, Georgia, Times, 'Times New Roman', serif;
 font-size: 30px;
}
.total-select{
 position: absolute;
 left: 20px;
 top: 25px;
 width: 45px;
 height: 45px;
}
.order-icon{
 position: absolute;
 right: 40px;
 top: 25px;
 width: 45px;
 height: 45px;
 background-size: 100%;
}
.cart-toatl-price{
 /* float: right; */
 margin-left:80px;
 text-align: center;
 width: 100px;
 font-family: Microsoft Yahei, Cochin, Georgia, Times, 'Times New Roman', serif;
 color: #b30000;
 font-size: 30px;
}
.pay {
 position: absolute;
 right: 0;
 background-color: #b30000;
 height: 100%;
 width: 200px;
 text-align: center;
 font-family: Microsoft Yahei, Cochin, Georgia, Times, 'Times New Roman', serif;
 font-size: 26px;
 color: #f2f2f2;
 text-align: center
}
 
.cart-no-data{
 padding:40px 0;
 color: #999;
 text-align: center;
}

官方提供的两个解决方案：
1、    对电脑的taro进行升级
      # taro
$ taro update self [version]
# npm
npm i -g @tarojs/cli@[version]
# yarn
yarn global add @tarojs/cli@[version]
2、    对项目的taro进行升级
 $ taro update project [version]
version 为选填，如：1.x.x/latest 等，将会直接更新到指定版本