小程序的picker省市区无法设置只显示省市，只能用普通的picker写一个
实现效果：
wxml
<!--省--><picker mode="selector" bindchange="bindPickerChange" value="{{index}}" range="{{sheng}}"><text class="picker">{{sheng[index]}}</text><text class='iconfont icon-xiangxia'></text></picker>
<!--市-->
<picker wx:if="{{shi[index2]}}" mode="selector" bindchange="bindShiChange" value="{{index2}}" range="{{shi}}">
<text class="picker">{{shi[index2]}}</text>
<text class='iconfont icon-xiangxia'></text>
</picker>
js
Page({data: {sheng: [],index: 0,shi: [],index2: 0,shengshiqu:{}},// 设置省的数据setSheng: function(){var shengArr = [];for (var i = 0; i < this.data.shengshiqu.data.length; i++) {shengArr.push(this.data.shengshiqu.data[i].value);}this.setData({sheng: shengArr,});},// 切换省bindPickerChange: function (e) {this.setData({index: e.detail.value,mineralMall: [],first: 0,index2: 0});// 设置市的数据var shiArr = [];var shiData = this.data.shengshiqu.data[this.data.index].children;if(shiData){for (var i = 0; i < shiData.length; i++) {shiArr.push(shiData[i].value);}this.setData({shi: shiArr})}else{this.setData({shi: []})}},// 切换市bindShiChange: function (e) {this.setData({index2: e.detail.value,mineralMall: [],first: 0});}">×