<view class="num-controller">
  <!-- <image src="images/minus.png" class="{{num <= min ?'hide': ''}}" bindtap="sub"></image> -->
  <button class="default" size="mini" hover-class="none" class="{{num <= min ?'hide': ''}}" bindtap="sub">-</button>
  <text class="num">{{num}}</text>
  <!-- <image src="images/plus.png" bindtap="add"></image> -->
  <button class="default" size="mini" hover-class="none" bindtap="add">+</button>
</view>