//wxml代码
<view class="bg-img" wx:for="{{ImgFileIDList}}" wx:key="index"  >
    <image lazy-load="true" mode='aspectFill' src="{{item}}" data-index="{{index}}" bindtap="ViewImage"/>
</view>
//js代码，展示预览图片
ViewImage(e) {
  let index = e.currentTarget.dataset.index
  //ImgFileIDList为自己要展示图片的数组    
  let imgAry = this.data.ImgFileIDList
    wx.previewImage({
      urls: imgAry,
      current: imgAry[index]
   })
},