微信小程序关于swiper问题求助

第一次发帖
我想实现一个轮播图，数据来源如下"data": [
    {
      "img_url": "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1522758300555&di=be2aa9242f01c56607d0d0a6822370d1&imgtype=0&src=http%3A%2F%2Fimgsrc.baidu.com%2Fimgad%2Fpic%2Fitem%2F4a36acaf2edda3ccdd9b40d50be93901203f92cc.jpg",
      "author": "苏霞",
      "content": "testtest",
      "maketime": "23:50:01"
    },
    {
      "img_url": "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1522758300555&di=be2aa9242f01c56607d0d0a6822370d1&imgtype=0&src=http%3A%2F%2Fimgsrc.baidu.com%2Fimgad%2Fpic%2Fitem%2F4a36acaf2edda3ccdd9b40d50be93901203f92cc.jpg",
      "author": "傅静",
      "content": "testtest",
      "maketime": "08:45:40"
    },
    {
      "img_url": "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1522758300555&di=be2aa9242f01c56607d0d0a6822370d1&imgtype=0&src=http%3A%2F%2Fimgsrc.baidu.com%2Fimgad%2Fpic%2Fitem%2F4a36acaf2edda3ccdd9b40d50be93901203f92cc.jpg",
      "author": "曾勇",
      "content": "testtest",
      "maketime": "01:37:33"
    }
  ]wxml文件如下 <view class="container">
 <swiper class="comment_swiper" current="{{current}}" bindchange="handleChange">
    <block wx:for="{{comments}}" wx:for-index="idx" wx:key="{{content_id}}">
      <swiper-item class="comment_swiper_item">
        <import src="templates/commentItem.wxml"/>
        <template is="comment_item" data="{{item: item}}"/>
      </swiper-item>
    </block>
 </swiper>
 </view>
<template name = "comment_item">
 <view class = "comment_card">
  <image class="comment_image" src = "{{item.img_url}}" mode = "aspectFill">
  </image>
  <view class = "comment_addition">
   <text class = "comment_author">{{item.author}}</text>
  </view>
  <view class = "comment_content">
   <text class = "comment_content_text">{{item.content}}</text>
  </view>
  <view class = "comment_maketime">{{item.maketime}}</view>
 </view>
</template>js代码如下data: {
    comments: [],
    current:0
  },  /**
   * 生命周期函数--监听页面加载
   */
  onLoad: function (options) {
    var that = this
    wx.request({
      url: 'https://www.easy-mock.com/mock/5aae0ff22b69a0654fe443f3/example/comment',
      method: 'GET',
      success: (res) => {
        that.setData({
          comments: res.data
        })
      }
    })
  },轮播图一直不能显示，请问各位大神问题出在哪里