支付宝小程序实现省市区三级联动

[{
 code:1,
 name:'北京',
 areas:[
  {
  code: 101,
  name:'朝阳区'
  },
  {
  code: 101,
  name:'丰台区'
  }
 ]
 },{
 code:2,
 name:'河北省',
 citys:[
  {
  code: 20,
  name:'石家庄市',
  areas:[{
   code:'201',
   name:'长安区'
  }]
  }
 ]
 }]

//ahtml
<popup show="{{showBottom}}" position="bottom" onClose="onPopupClose" className="cityPop">
 <view class="flex">
 <view onTap="onPopupClose">取消</view>
 <view onTap="bindMultiPickerChange" class="confrim">确定</view>
 </view>
 <view>
  <picker-view value="{{multiIndex}}" onChange="bindMultiPickerColumnChange" class="mypicker">
  <block a:for="{{multiArray}}">
   <picker-view-column key="{{index}}">
   <block a:for="{{item}}" a:for-item="colItem">
    <view key="{{colItem.code}}">{{colItem.name}}</view>
   </block>
   </picker-view-column>
  </block>
 </view>
 </popup>

// 滚动选择 
bindMultiPickerColumnChange(e) {
 // 注意处理直辖市自治区（nodeType =2 -- citys(null) areas(Array)）与其他省份(nodeType=1 -- citys(Array) areas(Array))
 let newColums = e.detail.value;
 let {
  multiIndex
 } = this.data;
 let newMultiIndex=[]
 if(multiIndex[0]!=newColums[0]) {
  newMultiIndex=[newColums[0], 0, 0]
  }else {
  newMultiIndex=[multiIndex[0], newColums[1],newColums[2]|| 0]
  };
 console.log('修改的列为', newMultiIndex);
 var data = {
  multiArray: this.data.multiArray,
  multiIndex: newMultiIndex
 };
 var data.multiArray[0] = this.data.provinces;
 if ((temp[data.multiIndex[0]].citys) && (temp[data.multiIndex[0]].citys).length > 0) {
  //如果第二列“市”的个数大于0,通过multiIndex变更multiArray[1]的值
  data.multiArray[1] = temp[data.multiIndex[0]].citys || [];
  var areaArr = (temp[data.multiIndex[0]].citys[data.multiIndex[1]]) && (temp[data.multiIndex[0]].citys[data.multiIndex[1]]).areas || [];
  //如果第三列“区”的个数大于0,通过multiIndex变更multiArray[2]的值；否则赋值为空数组
  data.multiArray[2] = areaArr.length > 0 ? areaArr : [];
 } else {
  //如果第二列“市”的个数不大于0，那么第二列“市”和第三列“区”都赋值为空数组
  //直辖市citys = null，直接赋值areas
  data.multiArray[1] = [];
  data.multiArray[2] = temp[data.multiIndex[0]].areas || [];
 }
 this.setData({
  multiArray: data.multiArray,
  multiIndex: data.multiIndex,
 });
 }

// 点击确定时 修改显示
bindMultiPickerChange: function(e) {
 let {
  multiArray,multiIndex
 } = this.data;
 let provinceName,
  cityName,
  districtName,
  provinceId,
  cityId,
  districtId;
 provinceName = multiArray[0][multiIndex[0]].name;
 cityName = multiArray[1].length > 0 ? multiArray[1][multiIndex[1]].name : '';
 districtName = multiArray[2].length > 0 ? multiArray[2][multiIndex[2]].name : '';
 provinceId = multiArray[0][multiIndex[0]].code;
 cityId = multiArray[1].length > 0 ? multiArray[1][multiIndex[1]].code : '';
 districtId = multiArray[2].length > 0 ? multiArray[2][multiIndex[2]].code : '';
 this.setData({
  provinceName,
  cityName,
  districtName,
  provinceId,
  cityId,
  districtId,
  region: provinceName + cityName + districtName,
  showBottom:false
 })
 }