微信小程序微商城（八）：缓存实现商品购物车功能

看效果

开发计划

1、商品详情页将商品信息放入缓存
2、购物车页面读取缓存获取商品信息
3、购物车商品计算和删除缓存商品

一、商品详情页将商品信息放入缓存

detail.wxml

<button data-goodid="{{goods.goodsId}}" class="button-addCar" bindtap="addCar" formType="submit">确定</button>

绑定bindtap事件将商品加入购物车。

detail.js

/**
   * 加入购物车
   */
  addCar: function (e) {
    var goods = this.data.goods;
    goods.isSelect=false;
    var count = this.data.goods.count;

    var title = this.data.goods.title;
    if (title.length > 13) {
      goods.title = title.substring(0, 13) + '...';
    }

    // 获取购物车的缓存数组（没有数据，则赋予一个空数组）  
    var arr = wx.getStorageSync('cart') || [];
    console.log("arr,{}", arr);
    if (arr.length > 0) {
      // 遍历购物车数组  
      for (var j in arr) {
        // 判断购物车内的item的id，和事件传递过来的id，是否相等  
        if (arr[j].goodsId == goodsId) {
          // 相等的话，给count+1（即再次添加入购物车，数量+1）  
          arr[j].count = arr[j].count + 1;
          // 最后，把购物车数据，存放入缓存（此处不用再给购物车数组push元素进去，因为这个是购物车有的，直接更新当前数组即可）  
          try {
            wx.setStorageSync('cart', arr)
          } catch (e) {
            console.log(e)
          }
          //关闭窗口
          wx.showToast({
            title: '加入购物车成功！',
            icon: 'success',
            duration: 2000
          });
          this.closeDialog();
          // 返回（在if内使用return，跳出循环节约运算，节约性能） 
          return;
        }
      }
      // 遍历完购物车后，没有对应的item项，把goodslist的当前项放入购物车数组  
      arr.push(goods);
    } else {
      arr.push(goods);
    }
    // 最后，把购物车数据，存放入缓存  
    try {
      wx.setStorageSync('cart', arr)
      // 返回（在if内使用return，跳出循环节约运算，节约性能） 
      //关闭窗口
      wx.showToast({
        title: '加入购物车成功！',
        icon: 'success',
        duration: 2000
      });
      this.closeDialog(); 
      return;
    } catch (e) {
      console.log(e)
    }
  }

二、购物车页面读取缓存获取商品信息

cart.wxml

<view class="J-shopping-cart-empty" hidden="{{iscart}}">
<view class="shopping-cart-empty">
        <view class="bg"></view> 
        <view class="cart"></view>
        <text class='empty-text'>购物车空空如也</text>  
        <p></p>
        <navigator url="/pages/goods/goods">
         <a  class="button button-primary" >
            去抢购
        </a>
        </navigator>
    </view>
</view> 

<view class="scroll" hidden="{{hidden}}">
<scroll-view class="scroll" scroll-y="true">
  <view class="separate"></view>
  <view wx:for="{{carts}}">
    <view class="cart_container">  
      <view  wx:if="{{!item.isSelect}}">
            <icon class="item-select" bindtap="switchSelect" data-index="{{index}}" data-id="{{index}}"  type="circle" size="20"></icon>
      </view>
      <view wx:elif="{{item.isSelect}}">
            <icon class="item-select" bindtap="switchSelect" data-index="{{index}}" data-id="{{index}}"  type="success" color="#f0145a" size="20"></icon>
      </view>

      <image class="item-image" src="{{item.imgUrl}}"></image>
      <import src="../template/template.wxml" />
      <view class="column">
        <text class="title">{{item.title}}</text>
         <image bindtap="delGoods" id="img{{index}}" data-index="{{index}}" src="../../images/del.png"></image> 
        <view class="row">
          <text class="sku-price">￥{{item.price * item.count}}</text>
          <view class="sku">
              <template is="quantity"  data="{{ ...item,index:index}}" /> 
          </view>
        </view>

      </view>
    </view>
    <view class="separate"></view>
  </view>
</scroll-view>
</view>
 <view class="bottom_total" hidden="{{hidden}}">
  <view class="bottom_line"></view>

  <view class="row">

    <view  wx:if="{{!isAllSelect}}">
            <icon class="item-allselect" bindtap="allSelect" type="circle" size="20"></icon>
      </view>
      <view wx:elif="{{isAllSelect}}">
            <icon class="item-allselect" bindtap="allSelect" type="success" color="#f0145a" size="20"></icon>
      </view>
    <text class="small_text">全选</text>
    <text>合计:￥ </text>
    <text class="price">{{totalMoney}}</text>
    <button class="button-red" bindtap="toBuy" formType="submit">去结算      </button>
  </view>
</view> 

cart.wxss

 @import "../template/template.wxss"; 
page{  
  background: #f3f4f5;  
  /* font-size: 37.5px;  */
}  

.column image {
  width:33rpx;
  height:35rpx;
  display:inline-block;
  overflow:hidden;
  float:right;
  margin-top: -40rpx;
  margin-left:400rpx;
} 
 .J-shopping-cart-empty{
    margin: 0;
    padding: 0;
    border: 0;
    font: inherit;
    font-size: 100%;
    vertical-align: baseline;
}
.shopping-cart-empty {
   height: 250px;
    padding-top: 3.2rem;
    padding-bottom: 1.6rem;
    background-color: #fff;
    text-align: center;
    position: relative;
}
 .shopping-cart-empty .bg{
    position: absolute;
    width: 16.29333rem;
    height: 6.73333rem;
    background: transparent url(data:image/png;base64,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);
    left: 50%;
    -webkit-transform: translateX(-50%);
    transform: translateX(-50%);
      background-size: 100%;

    top: 0;
}
 .shopping-cart-empty .cart{
        width: 5.83333rem;
    height: 7.46rem;
    background: transparent url(data:image/png;base64,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) no-repeat;
  background-size: 100%;
    margin: 0 auto;
}  

.shopping-cart-empty .button {
    width: 8.46667rem;
    height: 1.5rem;
    display: block;
    margin: 20rpx auto;
}

.empty-text {
    font-size: .64667rem;
    color: #222;
    margin-top: .53333rem;
    line-height: .74667rem;
    font-weight: 400;
}
.button-primary {
    border: 1px solid #de3c96;
    color: #de3c96;
    text-decoration: none;
    text-align: center;
    display: block;
    border-radius: .21267rem;
    line-height: 1.5rem;
    -webkit-appearance: none;
    background: none;
    padding: 0 .26667rem;
    margin: 0;
    white-space: nowrap;
    position: relative;
    text-overflow: ellipsis;
    font-size: .74333rem;
    font-family: inherit;
    cursor: pointer;
    user-select: none;
} 


.cart_container {
  display: flex;
  flex-direction: row;
  background-color: #FFFFFF;
  margin-bottom: 10rpx;
}
.scroll {
   margin-bottom: 120rpx; 
}
.column {
  display: flex;
  flex-direction: column;
}
.row {
  display: flex;
  flex-direction: row;
   align-items: center;
    /* margin-top: 40rpx;  */
  /* border: 1rpx solid #000000;  */
}
.sku {
  margin-left: 100rpx;
  position: absolute;
  right: 30rpx;
  margin-top: 30rpx; 
}
.sku-price {
  color: red;
  position: relative;
   margin-top: 30rpx; 
}
.price {
  color: red;
  position: relative;
}
.title {
  font-size: 32rpx;
  margin-top: 40rpx;
}
.small_text {
  font-size: 28rpx;
  margin-right: 40rpx;
  /* margin-left: 10rpx; */
  margin-left: 25rpx;
}
.item-select {
  width: 40rpx;
  height: 40rpx;
  margin-top: 90rpx;
  margin-left: 20rpx;
}
.item-allselect {
  width: 40rpx;
  height: 40rpx; 
  margin-left: 20rpx;
   margin-top:25rpx;   
}
.item-image {
  width: 180rpx;
  height: 180rpx;
  margin: 20rpx;
}
 .bottom_line {
  width: 100%;
  height: 2rpx;
  background: lightgray;
} 
.bottom_total {
  position: fixed;
  display: flex;
  flex-direction: column;
  bottom: 0;
  width: 100%;
  height: 120rpx;
  line-height: 120rpx;
  background: white;
  /* margin-top: 300rpx; */
  border-top: 1rpx solid #ccc;
  z-index: 99;
}
.button-red {
  background-color: #f0145a; 
  position: fixed;
  right: 0;
  color: white;
  text-align: center;
  display: inline-block;
  font-size: 30rpx;
  border-radius: 0rpx;
  width: 30%;
  height: 120rpx;
  line-height: 120rpx;
  /* border: 1rpx solid #ccc; */
}

cart.js

/**
   * 页面的初始数据
   */
  data: {
    carts: [], //数据 
    iscart: false,
    hidden: null,
    isAllSelect: false,
    totalMoney: 0,
  },
onShow: function () {
    // 获取产品展示页保存的缓存数据（购物车的缓存数组，没有数据，则赋予一个空数组）  
    var arr = wx.getStorageSync('cart') || [];
    console.info("缓存数据："+arr);
    // 有数据的话，就遍历数据，计算总金额 和 总数量  
    if (arr.length > 0) {
      // 更新数据  
      this.setData({
        carts: arr,
        iscart: true,
        hidden: false
      });
      console.info("缓存数据：" + this.data.carts);
    }else{
      this.setData({
        iscart: false,
        hidden: true,
      });
    }
  },

三、购物车商品计算和删除缓存商品

cart.js

//勾选事件处理函数  
  switchSelect: function (e) {
    // 获取item项的id，和数组的下标值  
    var Allprice = 0, i = 0;
    let id = e.target.dataset.id,

      index = parseInt(e.target.dataset.index);
    this.data.carts[index].isSelect = !this.data.carts[index].isSelect;
    //价钱统计
    if (this.data.carts[index].isSelect) {
      this.data.totalMoney = this.data.totalMoney + (this.data.carts[index].price * this.data.carts[index].count);
    }
    else {
      this.data.totalMoney = this.data.totalMoney - (this.data.carts[index].price * this.data.carts[index].count);
    }
    //是否全选判断
    for (i = 0; i < this.data.carts.length; i++) {
      Allprice = Allprice + (this.data.carts[index].price * this.data.carts[index].count);
    }
    if (Allprice == this.data.totalMoney) {
      this.data.isAllSelect = true;
    }
    else {
      this.data.isAllSelect = false;
    }
    this.setData({
      carts: this.data.carts,
      totalMoney: this.data.totalMoney,
      isAllSelect: this.data.isAllSelect,
    })
  },
  //全选
  allSelect: function (e) {
    //处理全选逻辑
    let i = 0;
    if (!this.data.isAllSelect) {
      this.data.totalMoney = 0;
      for (i = 0; i < this.data.carts.length; i++) {
        this.data.carts[i].isSelect = true;
        this.data.totalMoney = this.data.totalMoney + (this.data.carts[i].price * this.data.carts[i].count);

      }
    }
    else {
      for (i = 0; i < this.data.carts.length; i++) {
        this.data.carts[i].isSelect = false;
      }
      this.data.totalMoney = 0;
    }
    this.setData({
      carts: this.data.carts,
      isAllSelect: !this.data.isAllSelect,
      totalMoney: this.data.totalMoney,
    })
  },
  // 去结算
  toBuy() {
    wx.showToast({
      title: '去结算',
      icon: 'success',
      duration: 3000
    });
    this.setData({
      showDialog: !this.data.showDialog
    });
  },
  //数量变化处理
  handleQuantityChange(e) {
    var componentId = 
    var quantity = e.quantity;
    this.data.carts[componentId].count.quantity = quantity;
    this.setData({
      carts: this.data.carts,
    });
  },
  /* 减数 */
  delCount: function (e) {
    var index = e.target.dataset.index;
    console.log("刚刚您点击了加一");
    var count = this.data.carts[index].count;
    // 商品总数量-1
    if (count > 1) {
      this.data.carts[index].count--;
    }
    // 将数值与状态写回  
    this.setData({
      carts: this.data.carts
    });
    console.log("carts:" + this.data.carts);
    this.priceCount();
  },
  /* 加数 */
  addCount: function (e) {
    var index = e.target.dataset.index;
    console.log("刚刚您点击了加+");
    var count = this.data.carts[index].count;
    // 商品总数量+1  
    if (count < 10) {
      this.data.carts[index].count++;
    }
    // 将数值与状态写回  
    this.setData({
      carts: this.data.carts
    });
    console.log("carts:" + this.data.carts);
    this.priceCount();
  },
  priceCount: function (e) {
    this.data.totalMoney = 0;
    for (var i = 0; i < this.data.carts.length; i++) {
      if (this.data.carts[i].isSelect == true) {
        this.data.totalMoney = this.data.totalMoney + (this.data.carts[i].price * this.data.carts[i].count);
      }

    }
    this.setData({
      totalMoney: this.data.totalMoney,
    })
  },
  /* 删除item */
  delGoods: function (e) {
    this.data.carts.splice(e.target.id.substring(3),1);
    // 更新data数据对象  
    if (this.data.carts.length > 0) {
      this.setData({
        carts: this.data.carts
      })
      wx.setStorageSync('cart', this.data.carts);
      this.priceCount();
    } else {
      this.setData({
        cart: this.data.carts,
        iscart: false,
        hidden: true,
      })
      wx.setStorageSync('cart', []);
    }
  }

备注

微信小程序微商城系列

关注我们

如果需要源码可以关注“IT实战联盟”公众号并留言（微商城源码，5个字会收到源码下载地址，一定要看源码里面的操作手册会少走很多弯路），也可以加入交流群和作者互撩哦~~~