share_activity/components/topbar.wxml

<!--components/topbar.wxml-->
<view class="topbar topbar-class" style="top:{{capsuleTop + 3}}px; left: 28rpx;">
   <view class="back" catchtap="handleBack">
      <text class="back-iconfont back-color-class" style="{{backStyle}}" />
   </view>

   <view class="title topbar-title-class" style="{{titleStyle}}">{{title}}</view>

</view>