element table type="expand" 设置成按钮展开，并且设置背景色

上面主要要注意el-table ref的设置

methods:{
    toogleExpandCargo(row) {
      let $table = this.$refs.cargoTable;
      this.cargoTransList.map(item => {
        if (row.id != item.id) {
          $table.toggleRowExpansion(item, false);
        }
      });
      $table.toggleRowExpansion(row);
    },
}

还有就是设置隐藏列的背景色

.el-table >>> .el-table__expanded-cell[class*="cell"] {
  background: #f4f5f6;
}