<view class="descs">
  <view class="descs_item" wx:for="{{data}}" wx:key="key">
    <text class="descs_item_title">{{item.title}}:</text>
    <text class="descs_item_desc">{{item.desc}}</text>
  </view>
</view>

lifetimes: {
    ready: ()=> {
      var query = wx.createSelectorQuery();
      query.selectAll(".descs_item_title").boundingClientRect((rect) => {
        console.log(rect)
      }).exec()
    }
  }