<block wx:for="{{imageList}}" wx:for-item="imageItem" wx:for-index="idx">
  <view>
    <image src="{{imageItem}}" bindtap="proviewImage(imageItem)"></image>  
  </view>
</block>
proviewImage: function(imageItem){
   wx.previewImage({
  current:imageItem,
  urls: imageList
  })
}