微信小程序scroll-view仿拼多多横向滑动滚动条

<scroll-view scroll-x="true" class="scroll-view-x" style="padding-top:10rpx" scroll-with-animation="true" wx:if="{{tlist[currentTab].secondList}}" scroll-left='0' bindscroll="getleft">
    <!--内容区域-->
    <view>
     <view class="navigator_second" wx:for="{{tlist[currentTab].secondList}}" wx:for-item="childItem" bindtap="getProductList" data-id="{{childItem.id}}">
      <image class="navigator_icon" src="{{childItem.icon}}"></image>
      <text class="navigator_text">{{childItem.name}}</text>
     </view>
    </view>
    <view wx:if="{{tlist[currentTab].thirdList}}">
     <view class="navigator_second" wx:for="{{tlist[currentTab].thirdList}}" wx:for-item="childItem" data-id="{{childItem.id}}" bindtap="getProductList">
      <image class="navigator_icon" src="{{childItem.icon}}" ></image>
      <text class="navigator_text">{{childItem.name}}</text>
     </view>
    </view>
   </scroll-view >
   <!--滚动条部分-->
   <view wx:if="{{slideShow}}" class="slide">
    <view class='slide-bar' >
     <view class="slide-show" style="width:{{slideWidth}}rpx; margin-left:{{slideLeft<=1 ? 0 : slideLeft+'rpx'}};"></view>
    </view>
   </view>

//获取应用实例
var app = getApp();
Page({
 data: {
  navigate_type:'',//分类类型，是否包含二级分类
  slideWidth:'',//滑块宽
  slideLeft:0 ,//滑块位置
  totalLength:'',//当前滚动列表总长
  slideShow:false,
  slideRatio:''
 },
 onLoad: function () {
  var self = this ;
  var systemInfo = wx.getSystemInfoSync() ;
  self.setData({
   list: _list,
   windowHeight: app.globalData.navigate_type == 1 ? systemInfo.windowHeight : systemInfo.windowHeight - 35,
   windowWidth: systemInfo.windowWidth,
   navigate_type: app.globalData.navigate_type
  })
  //计算比例
  self.getRatio();
 },
 //根据分类获取比例
 getRatio(){
  var self = this ;
  if (!self.data.tlist[self.data.currentTab].secondList || self.data.tlist[self.data.currentTab].secondList.length<=5){
   this.setData({
    slideShow:false
   })
  }else{
   var _totalLength = self.data.tlist[self.data.currentTab].secondList.length * 150; //分类列表总长度
   var _ratio = 230 / _totalLength * (750 / this.data.windowWidth); //滚动列表长度与滑条长度比例
   var _showLength = 750 / _totalLength * 230; //当前显示红色滑条的长度(保留两位小数)
   this.setData({
    slideWidth: _showLength,
    totalLength: _totalLength,
    slideShow: true,
    slideRatio:_ratio
   })
  }
 } ,
 //slideLeft动态变化
 getleft(e){
  this.setData({
   slideLeft: e.detail.scrollLeft * this.data.slideRatio
  })
 } 
})

.scroll-view-x{
  background-color: #fff;
  white-space: nowrap;
}
.navigator_second{
 width:150rpx;
 text-align:center;
 display:inline-block;
 height:115rpx;
}
.navigator_icon{
 width:60rpx;
 height:60rpx;
}
.navigator_text{
 display:block;
 width:100%;
 font-size:24rpx
}
.slide{
 height:30rpx;
 background:#fff;
 with:100%;
 padding:14rpx 0 5rpx 0
}
.slide .slide-bar{
 width:230rpx;
 margin:0 auto;
 height:1.5px;
 background:#eee;
}
.slide .slide-bar .slide-show{
 height:100%;
 background-color:#ff6969;

}