wxmini/pages/components/navbar/navbar.wxml

<view class='nav-wrap nav-bgc-class' style='height: calc({{navBarHeight}}px - {{MenuButtonTop}}px); padding-top: {{MenuButtonTop}}px;'>
     <view class="nav-info" style="height: {{ MenuButtonheight }}px;">
        <view  bindtap='_navback' style="height: {{ MenuButtonheight }}px;" class="device-pic">
          <image wx:if='{{navbarData.showCapsule}}' bindtap=""  mode="heightFix"  src="./../../../img/goback.png"></image>
        </view>
        <text class="nav-title-class" style="height: {{ MenuButtonheight }}px; line-height: {{ MenuButtonheight }}px;">{{navbarData.title}}</text>
     </view>
  </view>