微信小程序下拉选项框

/**
   * 页面的初始数据
   */
  data: {
    shows: false, //控制下拉列表的显示隐藏，false隐藏、true显示
    selectDatas: ['消费账户', '平台返利账户', '微信钱包'], //下拉列表的数据
    indexs: 0, //选择的下拉列 表下标,
  },

  // 点击下拉显示框
  selectTaps() {
    this.setData({
      shows: !this.data.shows,
    });
  },
  // 点击下拉列表
  optionTaps(e) {
    let Indexs = e.currentTarget.dataset.index; //获取点击的下拉列表的下标
    console.log(Indexs)
    this.setData({
      indexs: Indexs,
      shows: !this.data.shows
    });

  },

<view class='fenlei'>
  <text>地址</text>
  <!-- 下拉框 -->
    <view class='select_box'>
      <view class='select' catchtap='selectTaps'>
        <text class='select_text'>{{selectDatas[indexs]}}</text>
        <!-- <image class='words_img' src='../../images/sanjiao.png'></image> -->
        <image class='select_img {{shows&&"select_img_rotate"}}' src='../../images/sanjiao.png'></image>
      </view>
      <view class='option_box' style='height:{{shows?(selectDatas.length>5?300:selectDatas.length*60):0}}rpx;'>
        <text class='option' style='{{indexs==selectDatas.length-1&&"border:0;"}}' wx:for='{{selectDatas}}' wx:key='this' data-index='{{index}}' catchtap='optionTaps'>{{item}}</text>
      </view>
    </view>
</view>

/* fenlei */
.fenlei{
  margin: 0 25rpx;
  height: 90rpx;
  line-height: 90rpx;
  border-bottom: 1rpx solid #e6e6e6;
  display: flex;
  align-items: center;
}
.fenlei text{
  font-size: 30rpx;
  color: #999999;
  margin-left: 15rpx;
}
/* 下拉框 */
.select_box {
  background: #fff;
  width: 620rpx;
  /* margin: 0 auto; */
  height: 90rpx;
  line-height: 90rpx;
  text-align: left;
  position: relative;
}

.select {
  box-sizing: border-box;
  width: 100%;
  height: 86rpx;
  /* border: 1px solid #efefef; */
  border-radius: 8rpx;
  display: flex;
  align-items: center;
  padding: 0 20rpx;
}

.select_text {
  font-size: 28rpx;
  flex: 1;
  color: rgb(102, 102, 102);
  line-height: 86rpx;
  height: 86rpx;
}

.select_img {
  width: 40rpx;
  height: 40rpx;
  display: block;
  transition: transform 0.3s;
}

.select_img_rotate {
  transform: rotate(180deg);
}

.option_box {
  position: absolute;
  top: 86rpx;
  width: 100%;
  /* border: 1px solid #efefef; */
  box-sizing: border-box;
  height: 0;
  overflow-y: auto;
  border-top: 0;
  background: #fff;
  transition: height 0.3s;
  z-index: 100;
}

.option {
  display: block;
  line-height: 40rpx;
  font-size: 28rpx;
  border-bottom: 1px solid #efefef;
  padding: 10rpx;
  color: rgb(102, 102, 102);
}