created() {
    this.$nextTick(() => {
      // this.initScroll()
      window.onscroll = 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
        if(scrollTop+windowHeight==scrollHeight){
          //写后台加载数据的函数
          console.log("距顶部"+scrollTop+"可视区高度"+windowHeight+"滚动条总高度"+scrollHeight);
        }  
      }
    })
  },