实现效果

实现过程

<div
    style="width: 100%; overflow: hidden; position: relative"
    id="container"
    ref="container"
    @mousewheel="handleScroll"
    :style="{ height: pageHeight + px }">
  <!--    表格-->
  <div class="loading-bottom" v-show="visibleLoading">
      <a-spin :spinning="visibleLoading" style="margin-right: 10px"></a-spin>正在加载数据
    </div>
</div>

data() {
          
   
  return {
          
   
    visibleLoading: false,
  }
},
mounted() {
          
   
  //ref指向对应div，不建议对window全局监听，会影响子div的滚动
  this.$refs.container.addEventListener(scroll, this.handleScroll);
},
beforeUnmount() {
          
   
  this.$refs.container.removeEventListener(scroll, this.handleScroll);
},
methods:{
          
   
  //滚轮监听
  handleScroll() {
          
   
    let listAllHeight =
      document.documentElement.scrollTop ||
      document.body.scrollTop + document.documentElement.scrollHeight ||
      document.body.scrollHeight;
    let containerHeight = document.querySelector(#container).scrollHeight;
    //46 + 62 + 75是表格距离页面顶部的剩余距离，跟个人布局有关
    let fieldHeight = document.querySelector(#left-field).scrollHeight + 46 + 62 + 75;
    if (
      (fieldHeight >= containerHeight && this.pageHeight !== fieldHeight) ||
      (containerHeight > fieldHeight && this.pageHeight !== containerHeight)
    ) {
          
   
      this.visibleLoading = true;
    }

    setTimeout(() => {
          
   
      if (listAllHeight === this.pageHeight && this.pageHeight < containerHeight) {
          
   
        this.pageHeight = this.pageHeight + 750;
      }
      if (this.pageHeight > containerHeight && containerHeight > fieldHeight) {
          
   
        this.pageHeight = containerHeight;
      }
      if (this.pageHeight > fieldHeight && fieldHeight >= containerHeight) {
          
   
        this.pageHeight = fieldHeight;
      }
      this.visibleLoading = false;
    }, 500);
  },
}

.loading-bottom {
          
   
  position: absolute;
  left: 255px;
  bottom: 0;
  height: 30px;
  padding: 5px 0;
  background-color: #d3dae6;
  width: calc(100% - 270px);
  text-align: center;
  font-size: 14px;
  font-weight: 500;
  border-radius: 2px;
}