Taro+react开发（9）--不要修改mode属性

   <Picker
          mode="selector"
          range={this.state.selectorProvince}
          onChange={this.onProvinceChange}
        >
          <AtList>
            <AtListItem title="省" extraText={this.state.provinceSel} />
          </AtList>
        </Picker>
        <Picker
          mode="selector"
          range={this.state.selectorCity}
          onChange={this.onCityChange}
        >
          <AtList>
            <AtListItem title="市" extraText={this.state.citySel} />
          </AtList>
        </Picker>