怎么在小程序中实现一个外卖订单界面

<view class="container">
  <view class="index-cont">
   <!-- 左边类型 -->
   <view class="index-left">
    <view wx:for="{{foodsList}}" wx:key="index" class="item {{curId === 'item'+index?'on':''}}" data-id="item{{index}}" bindtap="scrollToViewFn">{{item.name}}</view>
   </view>
   <!-- 右边产品 -->
   <scroll-view class="index-right" scroll-y="{{true}}" scroll-into-view="{{initView}}" scroll-with-animation="true" bindscroll="onPageScroll">
    <view class="boxs">
     <block wx:for="{{foodsList}}" wx:key="index">
      <view class="index-title" id="item{{index}}">{{item.name}}</view>
      <view class="item" wx:for="{{item.list}}" wx:key="ind" wx:for-item="itm" wx:for-index="ind" bindtap="showGoodDetail(itm)">
       <view class="pic"><image src="{{itm.pic}}" mode="aspectFill"></image></view>
       <view class="main">
        <view class="tit">{{itm.title}}</view>
        <view class="desc">{{itm.info}}</view>
        <view class="money">&yen;{{itm.price}}</view>
       </view>
       <view class="box">
        <view wx:if="{{itm.num !== 0}}" class="icon" catchtap="reduceNum(index, ind, itm)"><image src="../../../static/images/reduce-icon.png" alt=""></image></view>
        <input wx:if="{{itm.num !== 0}}" type="text" disabled wx:model="{{itm.num}}"/>
        <view class="icon" catchtap="addNum(index, ind, itm)"><image src="../../../static/images/add-icon.png" alt=""></image></view>
       </view>
      </view>
     </block>
    </view>
   </scroll-view>
  </view>
  <view class="index-cart">
   <view class="left">
    <view class="cart-num" wx:if="{{cartList.length === 0}}">
     <image src="../../../static/images/cart.png"></image>
    </view>
    <view class="cart-num on" wx:else bindtap="showCartMask">
     <image src="../../../static/images/cart.png"></image>
     <text>{{totalNum}}</text>
    </view>
    <view class="cart-money">&yen;{{totalMoney}}</view>
   </view>
   <view class="order-btn" bindtap="submitOrder">去结算</view>
  </view>

  <!--购物车弹窗-->
  <view class="dialog" wx:if="{{isShowCartMask && cartList.length !== 0}}" bindtap="hiddenCartMak()">
   <view class="boxs" catchtap="stopMaopao()">
    <view class="title-block">
     <text>已选商品</text>
     <view class="clear" bindtap="clearCart"><image src="../../../static/images/del.png"></image>清空</view>
    </view>
    <scroll-view class="content" scroll-y="{{true}}" scroll-with-animation="true">
     <block wx:for="{{cartList}}" wx:key="index">
      <view class="item" id="{{item.view}}">
       <view class="tit">{{item.name}}</view>
       <view class="right">
        <text>&yen;{{item.price}}</text>
        <view class="box">
         <view class="icon" bindtap="reduceCart(index, item)"><image src="../../../static/images/reduce-icon.png" alt=""></image></view>
         <input type="text" disabled wx:model="{{item.num}}"/>
         <view class="icon" bindtap="addCart(index, item)"><image src="../../../static/images/add-icon.png" alt=""></image></view>
        </view>
       </view>
      </view>
     </block>
    </scroll-view>
   </view>
  </view>
  <!--商品详情弹窗-->
  <view class="dialog1" wx:if="{{isShowDetail}}">
   <scroll-view class="detbox" scroll-y="{{true}}" scroll-with-animation="true">
    <image class="img" src="{{goodDetail.pic}}" mode="aspectFit"></image>
    <view class="box">
     <view class="tit">{{goodDetail.title}}</view>
     <view class="money">&yen;{{goodDetail.price}}</view>
     <view class="desc">{{goodDetail.info}}</view>
    </view>
    <view class="close" bindtap="hideDetail"><image src="../../../static/images/close_ico.png"></image></view>
   </scroll-view>
  </view>
 </view>

createPage({
 data: {
  foodsList: [], // 商品数据
  cartList: [], // 购物车数据
  isShowCartMask: false,
  totalNum: 0,
  totalMoney: 0,
  initView: 'item0', // 根据此变量的变化，控制左侧选中状态、右侧滑动
  curId: 'item0',
  isShowDetail: false,
  goodDetail: {},
  screenWidth: 0, // 手机屏幕宽度
  heightArray: [0] // 右侧每一个类型的高度区间数组
 },
 onLoad() {
  this.getGoodsData()
 },
 methods: {
  async getGoodsData() {
   const that = this
   const res = await getGoodsInfo({})
   this.foodsList = res
   wx.getSystemInfo({
    success: (ress) => {
     that.screenWidth = ress.windowWidth
    }
   })
   this.getHeightSection()
  },
  // 设置高度区间 所有单位转化为rpx
  getHeightSection() {
   const that = this
   let hg = 0
   for (let index = 0; index < that.foodsList.length - 1; index++) {
    hg += 70 + that.foodsList[index].list.length * 212
    that.heightArray.push(hg)
   }
  },
  // 获取高度区间的下标
  getHeightIndex(arr, hg) {
   const that = this
   arr.forEach((item, index) => {
    if (hg >= item) {
     that.setData({
      curId: 'item' + index
     })
    }
   })
  },
  // 左边菜单控制右边
  scrollToViewFn(e) {
   this.setData({
    initView: e.target.dataset.id,
    curId: e.target.dataset.id
   })
  },
  // 右边滚动控制左边
  onPageScroll(e) {
   const that = this
   let scrollTop = e.detail.scrollTop * 750 / that.screenWidth
   this.getHeightIndex(that.heightArray, scrollTop)
  },
  // 商品列表的减号点击
  reduceNum(index, ind, item) {
   const that = this
   let val = 'foodsList[' + index + '].list[' + ind + '].num'
   this.setData({
    [val]: item.num - 1
   })
   // 如果商品为0，就把当前商品在购物车清除
   // 如果不为0， 就将当前商品数量减1
   if (that.foodsList[index].list[ind].num === 0) {
    that.removeAarry(that.cartList, item.id)
   } else {
    that.cartList.forEach((itm, i) => {
     if (itm.id === item.id) {
      let value = 'cartList[' + i + '].num'
      that.setData({
       [value]: itm.num - 1
      })
     }
    })
   }
   this.computed()
  },
  // 商品列表的加号点击
  addNum(index, ind, item) {
   const that = this
   let val = 'foodsList[' + index + '].list[' + ind + '].num'
   this.setData({
    [val]: item.num + 1
   })
   // 如果商品为1，就把当前商品加入购物车
   // 否则， 就将当前商品数量加1
   if (that.foodsList[index].list[ind].num === 1) {
    let val = { id: item.id, name: item.title, price: item.price, num: 1, index: index, ind: ind, pic: item.pic }
    that.cartList.push(val)
   } else {
    that.cartList.forEach((itm, i) => {
     if (itm.id === item.id) {
      let value = 'cartList[' + i + '].num'
      that.setData({
       [value]: itm.num + 1
      })
     }
    })
   }
   this.computed()
  },
  // 购物车的减号点击
  reduceCart(index, item) {
   const that = this
   let val = 'foodsList[' + item.index + '].list[' + item.ind + '].num'
   let val1 = 'cartList[' + index + '].num'
   this.setData({
    [val]: item.num - 1,
    [val1]: item.num - 1
   })
   // 如果商品为0，就把当前商品在购物车清除
   // 如果不为0， 就将当前商品数量减1
   if (that.cartList[index].num === 0) {
    that.removeAarry(that.cartList, item.id)
   }
   this.computed()
  },
  // 购物车的加号点击
  addCart(index, item) {
   const that = this
   let val = 'cartList[' + index + '].num'
   that.setData({
    [val]: item.num + 1
   })
   this.computed()
  },
  // 清空购物车
  clearCart() {
   const that = this
   wx.showModal({
    title: '提示',
    content: '清空购物车？',
    success: function (res) {
     if (res.confirm) {
      that.setData({
       cartList: []
      })
      that.foodsList.forEach((item, i) => {
       item.list.forEach((itm, j) => {
        let value = 'foodsList[' + i + '].list[' + j + '].num'
        that.setData({
         [value]: 0
        })
       })
      })
      that.computed()
     }
    }
   })
  },
  // 计算选择商品总价格和总数量
  computed() {
   const that = this
   let num = 0
   let money = 0
   that.cartList.forEach(item => {
    num += item.num
    money += parseFloat(item.price) * item.num
   })
   that.setData({
    totalNum: num,
    totalMoney: money
   })
  },
  // 将数量为0的时候，对应商品在购物车中删除
  removeAarry(arr, id) {
   arr.forEach((item, index) => {
    if (item.id === id) {
     arr.splice(index, 1)
    }
   })
   return arr
  },
  showCartMask() {
   this.isShowCartMask = !this.isShowCartMask
  },
  hiddenCartMak() {
   this.isShowCartMask = false
  },
  stopMaopao() {
  },
  showGoodDetail(item) {
   this.goodDetail = item
   this.isShowDetail = true
  },
  hideDetail() {
   this.isShowDetail = false
  },
  // 订单提交
  submitOrder() {
  }
 }
})

<style lang='scss'>
@import '../../style/base.scss';
page {
 height: 100%;
}
.container {
 height: 100vh;
 background-color: #fff;
 box-sizing: border-box;
 overflow: hidden;
  .dialog1{
   width: 100%;
   height: 100vh;
   position: fixed;
   top: 0;
   left: 0;
   background-color: rgba(0,0,0, 0.5);
   z-index: 4;
    .detbox{
     position: fixed;
     bottom: 0;
     left: 0;
     right: 0;
     background-color: #fff;
     width: 100%;
     max-height: 700rpx;
     overflow-y: auto;
     color: #333;
     border-radius: 40rpx 40rpx 0 0;
      .img{
       width: 100%;
       height: 375rpx;
       background: rgba(0,0,0,0.6);
      }
      .box{
       padding: 20rpx 30rpx 40rpx;
       box-sizing: border-box;
        .tit{
         font-size: 28rpx;
         color: #333;
         font-weight: bold;
        }
        .money{
         font-size: 26rpx;
         color: #f00;
         margin: 10rpx 0;
        }
        .desc{
         font-size: 22rpx;
         color: #666;
         line-height: 32rpx;
        }
      }
      .close{
       width: 50rpx;
       height: 50rpx;
       position: absolute;
       right: 20rpx;
       top: 20rpx;
       display: flex;
       align-items: center;
       justify-content: center;
        image{
         width: 40rpx;
         height: 40rpx;
        }
      }
    }
  }
  .dialog{
   width: 100%;
   height: 100vh;
   position: fixed;
   top: 0;
   left: 0;
   background-color: rgba(0,0,0, 0.5);
   z-index: 2;
    .boxs{
     position: fixed;
     bottom: 80rpx;
     left: 0;
     right: 0;
     z-index: 6;
     background-color: #fff;
     width: 100%;
     max-height: 600rpx;
     color: #333;
      .title-block{
       padding: 0 30rpx;
       box-sizing: border-box;
       display: flex;
       align-items: center;
       justify-content: space-between;
       height: 70rpx;
       background: #EEF0F1;
        text{
         font-size: 26rpx;
         color: #666;
        }
        .clear{
         font-size: 22rpx;
         color: #888;
         display: flex;
         align-items: center;
          image{
           width: 24rpx;
           height: 24rpx;
           margin-right: 10rpx;
          }
        }
      }
      .content{
       width: 100%;
       max-height: 530rpx;
       overflow-y: auto;
       padding-bottom: 30rpx;
       box-sizing: border-box;
        .item{
         width: 690rpx;
         height: 80rpx;
         line-height: 80rpx;
         margin: 0 auto;
         position: relative;
         display: flex;
         align-items: center;
         justify-content: space-between;
          &::after{
           position: absolute;
           width: 100%;
           height: 1rpx;
           background: #f2f2f2;
           content: '';
           bottom: 1rpx;
           left: 0;
          }
          .tit{
           width: 400rpx;
           overflow: hidden;
           text-overflow: ellipsis;
           white-space: nowrap;
           font-size: 28rpx;
           color: #333;
          }
          .right{
           display: flex;
           justify-content: flex-start;
           align-items: center;
           height: 80rpx;
            text{
             font-size: 26rpx;
             color: #f00;
            }
            .box{
             display: flex;
             justify-content: flex-start;
             align-items: center;
             flex-wrap: nowrap;
             margin-left: 20rpx;
             height: 80rpx;
              .icon{
               width: 34rpx;
               height: 34rpx;
               display: flex;
               align-items: center;
               justify-content: center;
                image{
                 width: 34rpx;
                 height: 34rpx;
                }
              }
              input{
               width: 60rpx;
               height: 34rpx;
               border: none;
               color: #333;
               text-align: center;
               font-size: 26rpx;
              }
              
            }
          }
        }
      }
    }
  }
  .index-cont{
   height: calc(100vh - 80rpx);
   display: flex;
   justify-content: space-between;
   .index-left{
    width: 160rpx;
    height: 100%;
    background: #efefef;
     .item{
      font-size: 26rpx;
      color: #333;
      border-bottom: 1rpx dashed #666;
      height: 80rpx;
      line-height: 80rpx;
      padding: 0 20rpx;
      box-sizing: border-box;
       &.on{
        background: #fff;
       }
     }
   }
   .index-right{
    width: 590rpx;
    height: 100%;
     .boxs{
      padding: 0 30rpx;
      box-sizing: border-box;
      width: 100%;
     }
     .index-title{
      height: 70rpx;
      line-height: 70rpx;
      background: #f7f7f7;
      padding-left: 30rpx;
      font-size: 26rpx;
      color: #666;
      box-sizing: border-box;
     }
     .item{
      padding: 30rpx 0;
      box-sizing: border-box;
      display: flex;
      justify-content: space-between;
      position: relative;
      height: 212rpx;
       &::after{
        position: absolute;
        top: 0rpx;
        left: 0;
        background: #ccc;
        width: 100%;
        height: 1rpx;
        content: '';
       }
       .pic{
        width: 150rpx;
        height: 150rpx;
         image{
          width: 100%;
          height: 100%;
         }
       }
       .main{
        width: 380rpx;
        padding-left: 30rpx;
        box-sizing: border-box;
         .tit{
          font-size: 26rpx;
          color: #333;
          font-weight: bold;
         }
         .desc{
          font-size: 22rpx;
          color: #999;
          line-height: 30rpx;
          margin: 5rpx 0 10rpx;
          min-height: 65rpx;
         }
         .money{
          font-size: 28rpx;
          color: #f00;
         }
       }
       .box{
        display: flex;
        justify-content: flex-start;
        align-items: center;
        flex-wrap: nowrap;
        margin-left: 10rpx;
        height: 34rpx;
        position: absolute;
        right: 0;
        bottom: 30rpx;
         .icon{
          width: 34rpx;
          height: 34rpx;
          display: flex;
          align-items: center;
          justify-content: center;
           image{
            width: 34rpx;
            height: 34rpx;
           }
         }
         input{
          width: 60rpx;
          height: 34rpx;
          border: none;
          color: #333;
          text-align: center;
          font-size: 26rpx;
         }
         
       }
     }
   }
  }
  .index-cart{
   width: 100%;
   height: 80rpx;
   display: flex;
   align-items: center;
   justify-content: flex-start;
   position: relative;
   z-index: 3;
    .left{
     width: 470rpx;
     height: 100%;
     background: #3e3a39;
     display: flex;
     align-items: center;
     justify-content: flex-start;
      .cart-num{
       width: 100rpx;
       height: 100rpx;
       background: #6E6D6C;
       position: relative;
       padding:25rpx;
       box-sizing: border-box;
       border-radius: 100%;
       top: -30rpx;
       left: 22rpx;
        &.on{
         background: $base-color;
        }
        image{
         width: 50rpx;
         height: 50rpx;
        }
        text{
         font-size: 20rpx;
         color: #fff;
         display: inline-block;
         padding: 0 9rpx;
         box-sizing: border-box;
         position: absolute;
         right: 3rpx;
         top: -3rpx;
         height: 30rpx;
         line-height: 30rpx;
         border-radius: 30rpx;
         background: #f00;
        }
      }
      .cart-money{
       color: #fff;
       font-size: 30rpx;
       margin-left: 50rpx;
      }
    }
    .order-btn{
     width: 280rpx;
     height: 100%;
     background: $base-color;
     font-size: 28rpx;
     color: #fff;
     display: flex;
     align-items: center;
     justify-content: center;
    }
  }
}

goodLists: [
  {
    id: 'xx',  
    name: 'xx', // 商品类型
    list: [ // 当前商品类型对应的所有商品
      {
        id: 'xx',
        title: 'xx'，
        pic: 'xx',
        price: 'xx',
        detail: 'xx',
        num: '' // num是为了我方便对商品加减操作，让后端加的
      }
    ]
  }
]