本例从微信小程序的组件扒下来的。

WXML:

<view class="weui-cell">
  <view class="weui-cell__bd">
    <view class="weui-uploader">
      <view class="weui-uploader__hd">
        <view class="weui-uploader__title">点击可预览选好的图片</view>
        <view class="weui-uploader__info">{{imageList.length}}/{{count[countIndex]}}</view>
      </view>
      <view class="weui-uploader__bd">
        <view class="weui-uploader__files">
          <block wx:for="{{imageList}}" wx:for-item="image">
            <view class="weui-uploader__file">
              <image class="weui-uploader__img" src="{{image}}" data-src="{{image}}" bindtap="previewImage"></image>
            </view>
          </block>
        </view>
        <view class="weui-uploader__input-box">
          <view class="weui-uploader__input" bindtap="chooseImage"></view>
        </view>
      </view>
    </view>
  </view>
</view>

WXSS:

page {
  line-height: 1.6;
  font-family: -apple-system-font, "Helvetica Neue", sans-serif;
}
icon {
  vertical-align: middle;
}
.weui-cell {
  padding: 10px 15px;
  position: relative;
  display: -webkit-box;
  display: -webkit-flex;
  display: flex;
  align-items: center;
}
.weui-cell_input {
  padding-top: 0;
  padding-bottom: 0;
}
.weui-uploader__hd {
  display: -webkit-box;
  display: -webkit-flex;
  display: flex;
  padding-bottom: 10px;
  align-items: center;
}
.weui-uploader__title {
  flex: 1;
}
.weui-uploader__info {
  color: #b2b2b2;
}
.weui-uploader__bd {
  margin-bottom: -4px;
  margin-right: -9px;
  overflow: hidden;
}
.weui-uploader__file {
  float: left;
  margin-right: 9px;
  margin-bottom: 9px;
}
.weui-uploader__img {
  display: block;
  width: 79px;
  height: 79px;
}
.weui-uploader__input-box {
  float: left;
  position: relative;
  margin-right: 9px;
  margin-bottom: 9px;
  width: 77px;
  height: 77px;
  border: 1px solid #d9d9d9;
}
.weui-uploader__input-box:before, .weui-uploader__input-box:after {
  content: " ";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: #d9d9d9;
}
.weui-uploader__input-box:before {
  width: 2px;
  height: 39.5px;
}
.weui-uploader__input-box:after {
  width: 39.5px;
  height: 2px;
}
.weui-uploader__input {
  position: absolute;
  z-index: 1;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
}

JS

Page({
  data: {
    imageList: [],
    countIndex: 3,//最多上传图片的数量
    count: [1, 2, 3, 4, 5, 6, 7, 8, 9]
  },
  chooseImage: function () {
    var that = this;
    wx.chooseImage({
      count: this.data.count[this.data.countIndex],
      success: function (res) {
        console.log(res)
        that.setData({
          imageList: res.tempFilePaths
        })
      }
    })
  },
  previewImage: function (e) {
    var current = e.target.dataset.src
    wx.previewImage({
      current: current,
      urls: this.data.imageList
    })
  }
})