<view class="right-nav">
  <view bindtap="getCurrentCode" class="{{chooseIndex == index " wx:for="{{cityList}}" style="height:{{codeHeight}}px" data-code="{{item.code}}" data-index="{{index}}">
  {{item.code}}
  </view>
</view>

<view class="city-layer {{isShowLayer ">
 {{codeY}}
</view>

<view class="current-choose-city">当前选择机场：{{chooseCity}}</view>
<scroll-view class="city-scroll" scroll-y="true" scroll-into-view="{{codeY}}" scroll-with-animation="true" style="height:{{cityHeight}}px" bindscroll="scroll">
  <view class="city-box" wx:for="{{cityList}}" wx:key="{{item.code}}">
    <view class="city-code" id="{{item.code}}">{{item.code}}</view>
    <view class="city-list" wx:for="{{item.cityList}}" wx:for-item="city" bindtap="getChooseCity" data-city="{{city}}"> 
       {{city}} 
    </view> 
  </view>
</scroll-view>

.current-choose-city{
 position: fixed;
 width: 100%;
 height: 50px;
 line-height: 50px;
 padding: 0 10px;
 top: 0;
 left: 0;
 background-color: #fff;
 z-index: 10;
}
.right-nav{
 width: 30px;
 color: #888;
 text-align: center;
 position: fixed;
 bottom: 0;
 right: 0;
 background-color: rgb(200, 200, 200);
 z-index: 9;
}
.city-scroll{padding-top: 50px;}
.city-code{
 background-color: #f7f7f7;
}
.city-list,.city-code{
 height: 39px;
 line-height: 40px;
 padding: 0 30px 0 10px;
 overflow: hidden;
 border-bottom: 1px solid #c8c7cc;
}
.city-list-active{color:#007aff;}

/*提示点击的字母 */
.city-layer{
 width: 70px;
 height: 70px;
 line-height: 70px;
 text-align: center;
 border-radius: 50%;
 color: #fff;
 background-color: rgba(0, 0, 0, .7);
 position: fixed;
 top: calc(50% - 35px);
 left:calc(50% - 35px);
 z-index: 11;
}
.layer-hide{display: none;}

var city_list = require('./city.js');

Page({
 data: {
  cityList: city_list.city,
  chooseCity: '您还未选择机场！',
  isShowLayer: false,
  chooseIndex: 0,
  codeY: 'A',
  codeHeight: null,
  cityHeight:null
 },
 onLoad (options) {
  var windowHeight = wx.getSystemInfoSync().windowHeight;
  this.setData({ 
   codeHeight: (windowHeight - 50) / this.data.cityList.length,
   cityHeight: windowHeight - 50,
  });
 },
 getCurrentCode(e){
  var self = this;
  this.setData({ 
   codeY: e.target.dataset.code,
   chooseIndex: e.target.dataset.index,
   isShowLayer: true 
  })
  setTimeout(() => {
   self.setData({ isShowLayer: false })
  },500);
 },
 getChooseCity(e){
  this.setData({ chooseCity: e.target.dataset.city });
 }
})