微信小程序下拉刷新组件加载图片(三个小点)不显示刷新状态的问题

 "enablePullDownRefresh":true,
  "backgroundTextStyle": "dark"

{
  "usingComponents": {},
  "navigationBarTitleText": "采集列表",
  "enablePullDownRefresh":true,
  "backgroundTextStyle": "dark"
}

    /**
     * 页面相关事件处理函数--监听用户下拉动作
     */
    onPullDownRefresh: function () {
        this.onRefresh()
    },

    onRefresh:function(){
        //导航条加载动画
        wx.showNavigationBarLoading();
        //重置分页加载页面
        this.data.current_page=1
        //网络请求数据
        this.getManagerSampleListFunction()
        //超时隐藏
        setTimeout(function () {
            wx.hideNavigationBarLoading();
            //停止下拉刷新
            wx.stopPullDownRefresh();
        }, 2000);
    },

  //网络请求数据
   getManagerSampleListFunction() {
       api.fetchManngerSampleList().then(res => {
           //停止下拉刷新
           wx.hideNavigationBarLoading();
           //停止下拉刷新
           wx.stopPullDownRefresh();
           //处理数据 
           if (this.data.current_page == 1) {
               
           } else {
               
           }
       })
   },