Agency_WxApp/miniprogram/components/portsBar/portsBar.wxml

<view class="ports df jcc">
  <view wx:for="{{arr}}" wx:key="{{key}}" class="port {{index==0?'first-port':''}} {{index==arr.length-1?'last-port':''}} {{currentIndex==index?'current-port':''}} {{arr.length==1?'one-port':''}}" catchtap="changeTab" data-index="{{index}}">{{item[label]}}</view>
</view>