<view class=“section”>

  <view class=“section__title”>flex-direction: row</view>

  <view class=“flex-wrp” style=“flex-direction:row;”>

    <view class=“flex-item bc_green”>1</view>

    <view class=“flex-item bc_red”>2</view>

    <view class=“flex-item bc_blue”>3</view>

  </view>

</view>

<view class=“section”>

  <view class=“section__title”>flex-direction: column</view>

  <view class=“flex-wrp” style=“height: 300px;flex-direction:column;”>

    <view class=“flex-item bc_green”>1</view>

    <view class=“flex-item bc_red”>2</view>

    <view class=“flex-item bc_blue”>3</view>

  </view>

</view>

用的官网的文档