小程序改变swiper的指示点的样式

wxml

<view class="wrap">
 <swiper class="swipers" autoplay="{{autoplay}}" current="{{currentSwiper}}" bindchange="swiperChange"> 
  <block wx:for="{{imgUrls}}"> 
   <swiper-item> 
     <image src="{{item}}" class="slide-image" width="100%" height="150" ></image> 
   </swiper-item> 
  </block> 
 </swiper> 
 <!--重置小圆点的样式 -->
 <view class="dots"> 
  <block wx:for="{{imgUrls}}"> 
   <view class="dot{{index == currentSwiper ? ' active' : ''}}"></view> 
  </block> 
 </view> 
</view>

css

.wrap {
 height: auto;
 position: relative;
 width: 100%;
}
.swipers {
 height: 350rpx;
 width: 100%;
}
.slide-image {
 display: block;
 width: 100%;
 height: 100%;
}
/*用来包裹所有的小圆点 */
.dots {
 width: 300rpx;
 height: 5rpx;
 display: flex;
 flex-direction: row;
 position: absolute;
 /* left: 320rpx; */
 background: #000;
 bottom: 20rpx;
}
/*未选中时的小圆点样式 */
.dot {
 width: 100rpx;
 height: 5rpx;
 /* border-radius: 50%; */
 /* margin-right: 26rpx; */
 /* background-color: white; */
}
/*选中以后的小圆点样式 */
.active {
 width: 100rpx;
 height: 5rpx;
 background-color: coral;
}

js

Page({
  data: {
    imgUrls: [
      'http://img02.tooopen.com/images/20150928/tooopen_sy_143912755726.jpg',
      'http://img06.tooopen.com/images/20160818/tooopen_sy_175866434296.jpg',
      'http://img06.tooopen.com/images/20160818/tooopen_sy_175833047715.jpg'
    ],
    currentSwiper: 0,
    autoplay: true
  },
  swiperChange: function (e) {
    this.setData({
      currentSwiper: e.detail.current
    })
  }
})