el-table 固定前n行 配合 max-height 生效

 :row-class-name="TableRowClassName"   加上类名 

   <el-table
        :data="computedTableList"
        border
        style="width: 100%"
        :row-class-name="TableRowClassName"
        max-height="800">
        <el-table-column fixed prop="name" align="center" width="185" :key="1">
 </el-table>

  function TableRowClassName ({ row, rowIndex }) {
    if (row.isFalseData) {
      return 'top_bgc fixed-row'
    }
    if (row.isSticky) {
      return 'sticky_bgc'
    }
  }


  // 顶部固定 悬浮
  :deep(.el-table tr.el-table__row.fixed-row) {
    position: sticky; //粘性定位
    position: -webkit-sticky;
    z-index: 999;
  }
  :deep(.el-table tr.el-table__row.fixed-row:nth-of-type(1)) {
    top: 0;  
  }
  :deep(.el-table tr.el-table__row.fixed-row:nth-of-type(2)) {
    top: 94px;  // 根据每一行的高度自行调整
  }
  :deep(.el-table tr.el-table__row.fixed-row:nth-of-type(3)) {
    top: 188px;
  }