- 当前 Bug 的表现（可附
上截图）

- 预期表现

- 复现路径

- 提供一个最简复现 Demo

<!-- 图片预览 -->

<view wx:for="{{pictures}}" wx:key="unique">

<image  src="{{item}}" data-index="{{index}}" bindtap="previewImage"></image>

</view>

data: {

    pictures: [

    'http://res.iiiview.net/ugc/file/2017/09/11/d6wyvqit2rlhsk7z2qp7vzq6h83isb7i.jpg',

    'http://res.iiiview.net/ugc/file/2017/06/21/prw65lf7or0asm1kxdn10raqqjpglg3o.jpg',

    'https://p0.meituan.net/movie/0c49f98a93881b65b58c349eed219dba290900.jpg',

    'https://p1.meituan.net/movie/45f98822bd15082ae3932b6108b17a01265779.jpg',

    'https://p1.meituan.net/movie/722de9a7b0c1f9c262162d87eccaec7c451290.jpg',

    'https://p0.meituan.net/movie/cb9be5bbedb78ce2ef8e83c93f83caca474393.jpg',

    'https://p1.meituan.net/movie/a852b992cdec15319c717ba9fa9b7a35406466.jpg',

    'https://p1.meituan.net/movie/dc1f94811793e9c653170cba7b05bf3e484939.jpg'

    ],

},

// 图片预览

previewImage: function (e) {

    var that = this,

    //获取当前图片的下表

    index = e.currentTarget.dataset.index,

    //数据源

    pictures = this.data.pictures;

    console.log(pictures[index])

    wx.previewImage({

    //当前显示下表

    current: pictures[index],

    //数据源

    urls: pictures

    })

},