這是wxml, bindchange是實時繫結輪播改變事件

<swiper class='sw-tu' circular="true" current="0" bindchange='onSlideChangeEnd'>  
    <swiper-item class="sw-tuone" wx:for="{{list.img2}}">  
      <image class='sw-photo' src="{{item}}" />  
    </swiper-item>  
  </swiper>

這是js, e.detail.current 是圖下標，從零開始！

onSlideChangeEnd: function (e) {
    var that = this;
    that.setData({
      index: e.detail.current + 1
    })
  },