微信小程序实现字母索引菜单

<view class="container">

<view class="content">
  <view class="all-food">
    <view class="food">全部食物</view>
      <scroll-view class="food-scroll" scroll-y="true" scroll-into-view="{{toView}}" scroll-with-animation="true">
        <view class="food-list">

            <view wx:for="{{foodList}}" wx:key="{{index}}" id="{{'food'+index}}"  data-title="{{item.title}}">
              <view class="nav-text">
                <text>{{item.title}}</text>
              </view>
              <view class="show-food">
                <text wx:for="{{item.lists}}" wx:key="{{index}}">{{item}}</text>
              </view>
            </view>

        </view>
      </scroll-view>
    </view>

  <view class="search-nav"  bindtouchstart="touchStart" bindtouchmove="touchMove" bindtouchend="touchEnd">
    <text bindtap="foodScroll" data-index="{{index}}" wx:for="{{searchNav}}" wx:key="{{index}}">{{item}}</text>
  </view>
</view>
</view>

let foodList = require('../../utils/common');
Page({

  /**
   * 页面的初始数据
   */
  data: {
    foodList:[],
    toView:'',
    searchNav:[]
  },

  getFoodList(){
        let searchNav = this.data.searchNav
        for(let i in foodList.foodList){
            searchNav.push(foodList.foodList[i].title)
        }
        this.setData({
            foodList:foodList.foodList,
            searchNav:searchNav
        })

  },
  
  foodScroll(e){
        let index = e.currentTarget.dataset.index;
        this.setData({
            toView:`food${index}`
        })

    },
  /**
   * 生命周期函数--监听页面加载
   */
  onLoad: function (options) {
    this.getFoodList();
  },

  /**
   * 生命周期函数--监听页面初次渲染完成
   */
  onReady: function () {
    
  },

  /**
   * 生命周期函数--监听页面显示
   */
  onShow: function () {
    
  },

  /**
   * 生命周期函数--监听页面隐藏
   */
  onHide: function () {
    
  },

  /**
   * 生命周期函数--监听页面卸载
   */
  onUnload: function () {
    
  },

  /**
   * 页面相关事件处理函数--监听用户下拉动作
   */
  onPullDownRefresh: function () {
    
  },

  /**
   * 页面上拉触底事件的处理函数
   */
  onReachBottom: function () {
    
  },

  /**
   * 用户点击右上角分享
   */
  onShareAppMessage: function () {
    
  }
})

 /* pages/city/city.wxss */
 .container {
  padding: 0 5rpx;
  display: flex;
  justify-content:row;
  background-color: #fff;
}

.content{
  margin-top: 30rpx;
  width: 100%;
}

.food{
  font-size: 40rpx;
  padding-bottom: 10rpx;
  border-bottom: 1rpx solid #fff;
  height:30rpx;
  line-height:30rpx;

}

.food-scroll {
  left: 0;
  position: fixed;
  height: 100%;
  width: 720rpx;
}

.show-food{
  display: flex;
  flex-direction: column;
  justify-content: left;
  
}
.show-food text{
  margin-top: 10rpx;
  margin-bottom: 10rpx;
  font-size: 32rpx;
  border-bottom: 1rpx solid silver;
}

.search-nav{
  position: fixed;
  top: 120rpx;
  bottom: 5rpx;
  right: 5rpx;
  display:flex;
  flex-direction: column;
  justify-content: space-around;
}
.search-nav text{
  text-align: center;
  font-size: 24rpx;
}

let food = [     
  {
      "title":"A",
      "lists":[
      "艾蒿"
        ]
  },
  {
      "title":"B",
      "lists":["白萝卜","白瓜","白菜","菠菜","白笋","百合","摈榔","白花菜","白沙蒿","百里香","豆腐柴","芭蕉","菠萝","白金瓜"
        ]
  },
  {
      "title":"C",
      "lists":["蚕豆","菜花","春笋","慈菇","刺儿菜","草菇","草莓","橙","茶肠","草鱼","鲳鱼"
        ]
  },
  {
      "title":"D",
      "lists":["豆腐","豆浆","豆腐脑","豆奶","豆汁","豆腐丝","豆腐卷","豆腐皮","豆腐干","豆干尖","豆沙","刀豆","豆角","冬瓜","大蒜","大葱","大白菜","冬寒菜","冬笋","豆瓣菜","大薯","大车前","地肤","大黄","大麻","大红菇","地衣","蛋清肠"
        ]
  },
  {
      "title":"E",
      "lists":["鹅肉","鹅肝","鹅腿","鹅蛋"]
  },
  {
      "title":"F",
      "lists":["粉丝","腐竹","番茄","方瓜","佛手瓜","分葱","发菜"
        ]
      
  },
  {
     "title":"G",
      "lists":["挂面","甘薯","甘蓝","观达菜","枸杞","柑","桂圆","橄榄","桂鱼","鲑鱼"]
     
  },
  {
     "title":"H",
      "lists":["花卷","黄豆","花豆","红萝卜","花叶萝卜","胡萝卜","荷兰豆","黄豆芽","葫子","葫芦","葫芦条","黄瓜","茴香","黑笋","花案菜","槐花","黄麻叶","苦苦菜","猴头菇","黄菇","海带","海棠","黄皮果","火腿肠","火鸡","火鸡肝","火鸡腿","黄油","黄鳝","鳇鱼","黄骨鱼"
       ]
  },
  {
     "title":"J",
      "lists":["豇豆","芥菜头","节瓜","金瓜","金丝瓜","韭菜","韭黄","韭苔","金针菜","菊笋","茭白","姜","蕨菜","金针菇","鸡肉","鸡腿","鸡心","鸡翅","鸡肾","鸡脖"]
           
  },
  {
     "title":"K",
      "lists":["空锅饼","苦瓜","苦菜","口蘑","葵花籽"]

  },
  {
     "title":"L",
      "lists":["烙饼","绿豆饼","龙豆","绿豆芽","辣椒","萝卜缨","落葵","轮叶党参","罗勒","梨","梅","荔枝","栗子","腊肉","驴肉","驴鞭","驴心","骆驼肉","骆驼掌","骆驼蹄", ]

  },
  {
      "title":"M",
      "lists":["面条","馒头","木薯","梅豆","木豆","毛豆","毛笋","马蹄","马齿苋","马兰头","麦瓶草",
      "蘑菇","木耳","面蛋","芒果","木瓜","马肉","马心"
  ]
  },
  {
     "title":"N",
      "lists":["脑豆","奶茄子","南瓜","牛至","柠檬","牛肉","牛肋","牛腿","牛里脊","牛蹄筋", "牛鞭","牛肚","牛肝","牛肺","牛脑","牛骨","牛大肠","牛心","牛肾","牛肉干", "牛肉松",
                    ]
  },
  {
   "title":"O",
      "lists":["藕粉","藕"]
  },
  {
     "title":"P",
      "lists":["扁豆","蒲菜","喷瓜","蒲公英","苹果","葡萄","葡萄干"]

  },
  {
     "title":"Q",
      "lists":["荞麦","青豆","茄子","秋葵","青蒜","芹菜","掐不齐","清明菜","球茎茴香","启明菜叶","青菇"
  ]
  },
  {
     "title":"R",
      "lists":["人参果","肉松","儿童肠"]
  },
  {
     "title":"S",
      "lists":["烧饼","水面筋","马铃薯","素火腿","素大肠","素鸡","素鸡丝卷","素什锦","四季豆","蛇瓜","丝瓜","笋瓜","蒜苗","生菜","水芹菜","山药","石头菜","沙参叶","松菇","沙果","酸刺","石榴","柿子","柿饼","桑葚"
       ]
           
  },
  {
     "title":"T",
      "lists":["通心面","甜椒","甜菜叶","茼蒿","汤菜","土三七","苔菜","桃","甜瓜","兔肉"
       ]
  },
  {
   "title":"W",
   "lists":["豌豆","乌菜","莴笋","歪头菜","梧桐子","无花果","午餐肉"
    ]
  },
  {
     "title":"X",
      "lists":["小豆粥","西葫芦","小葱","小白菜","西兰花","香菜","苋菜","夏枯草","香椿","香茅","小旋花","竹叶菜","香菇","香蕉","西瓜","杏仁","橡子","叉烧肉","咸肉","香肠"
       ]
           
  },
  {
     "title":"Y",
      "lists":["油饼","油条","油面筋","薏米","玉米","芸豆","洋葱","油菜","芋头","洋姜","野葱","野韭菜","营野菊口","野蒜","野苋菜","榆钱","鱼腥草","羊肚菌","银耳","樱桃","柚","杨梅"
       ]
     
  },
  {
      "title":"Z",
      "lists":["竹笋"," 榛子","珍珠白菇","紫菜","枣","猪肉","芝麻","猪大排","猪耳","猪蹄","猪头","猪肘","猪肺","猪肝","猪脑","猪皮","猪舌","猪腰","猪心","猪血"
       ]
  }
   ]
module.exports = {
   foodList:food
}