code: function octoParseImgTap(e) {
    var that = this;
    var nowImgUrl = e.currentTarget.dataset.src;
    var tagFrom = e.currentTarget.dataset.from;
  
    if (typeof tagFrom != 'undefined' && tagFrom.length > 0) {
      wx.previewImage({
        current: nowImgUrl,
        // 当前显示图片的http链接
        // urls: that.data[tagFrom].imageUrls // 需要预览的图片http链接列表
        urls: [nowImgUrl]
      });
    }
  }
docs: 图片点击事件