mounted() { 
  const _this = this;
  window.addEventListener('scroll', function () {
    //变量scrollTop是滚动条滚动时，距离顶部的距离
    var scrollTop = document.documentElement.scrollTop || document.body.scrollTop;

    //变量windowHeight是可视区的高度
    var windowHeight = document.documentElement.clientHeight || document.body.clientHeight;

    //变量scrollHeight是滚动条的总高度
    var scrollHeight = document.documentElement.scrollHeight || document.body.scrollHeight;

    //滚动条到底部的条件     console.log(scrollTop,windowHeight,scrollHeight);
    
    if (scrollTop + windowHeight+1 >= scrollHeight) {
      //到了这个就可以进行业务逻辑加载后台数据了
      // _this.footerText = '我是有底线的';
      // _this.pagination.pageIndex = _this.pagination.pageIndex + 1
      // _this.GetOwnCoursePageListPush()   数果数组是请求的，则执行请求

      //达到条件停止自动加载
      _this.txtList = [..._this.txtList, ..._this.addList]
      if (_this.txtList.length >= 60) {
        _this.addList = []     
      }
    }
  }) 
}