代码：

wxml:
<view class="segment-group">
  <scroll-view enable-flex  class="segment-header {{scrollTop > 200?'scrollTop':''}}">
    <block wx:for="{{items}}" wx:key="item">
      <view class="segment-item active" wx:if="{{currentIndex === index}}" bindtap="onItemTapEvent"  data-index="{{index}}">{{item}}</view>
      <view class="segment-item" wx:else bindtap="onItemTapEvent" data-index="{{index}}">{{item}}</view>
    </block>
  </scroll-view>
  <block wx:for="{{items}}" wx:key="item">
      <slot name="{{index}}" wx:if="{{currentIndex === index}}"></slot>
    </block>
</view>
wxss:
.scrollTop{
  position:fixed;
  display:flex;
  justify-content:space-evenly;
  top:0;
  left:0;
  right:0;
  border-radius:none;
}
js:
onPageScroll:function(event){
    console.log(event);
    var scrollTop=event.scrollTop;
    this.setData({
      scrollTop:scrollTop,
    })
  },