smart-canteen/commpents/navbar/index.wxml

<cover-view class="nav-wrap" style='height: {{height*2 + 25}}px;'>
  <!-- 导航栏 中间的标题 -->
  <cover-view class='nav-title' style='line-height: {{height*2 + 45}}px;'>
    {{navbarData.name}}
  </cover-view>
  <cover-view style='display: flex; justify-content: space-around;flex-direction: column;' wx:if="{{needBack}}">
    <!-- 导航栏  左上角的返回按钮 -->
    <cover-view class='nav-capsule' style='height: {{height*2 + 45}}px;'>
      <cover-view bindtap='_navback'>
        <cover-image src='/image/back.png' mode='aspectFill' class='back-pre'></cover-image>
      </cover-view>
    </cover-view>
  </cover-view>
</cover-view>