微信小程序导航栏，下面内容滑动，上册导航栏跟着滑动，内容随着导航栏滑动

16.类似微信导航栏滑动.png
今日头条导航栏，下面滑动上面跟着滑动

• index.wxml

<swiper class="content"
 style="height:{{height}}px"
 bindchange="change"
 current-item-id="{{docid}}"
 duration="100"
 >  
  <swiper-item data-key="{{item.id}}"
  wx:for="{{title}}"
  wx:key="index"
  item-id="{{item.id}}">

• index.js

//bindchange事件
change:function(){
    // 获取当前索引
    var index = e.detail.current;
    // 51是每个导航的宽度，240是scroll-view的宽度 滚动条所有的距离-240
    if (index * 51 > 240 && index * 51 < 561) {
      this.setData({ left: 51 * (index - 3) })
    } else if (index * 51 < 240) {
      this.setData({ left: 0 })
    } else if (index * 51 > 561) {
      this.setData({ left: 51 * (index - 1) })
    }
    var that = this;
    var docid = e.detail.currentItemId;
    this.setData({ docid: docid })
    var title = that.data.title;
    for (let i = 0; i < that.data.title.length; i++) {
      if (title[i].id == docid) {
        that.setData({ current: title[i].key });
      }
    }
}