element-ui中的el-table底部固定指定行

1，固定一行合计的情况

   https://element.eleme.cn/#/zh-CN/component/table

  直接使用官方文档上的summary-method

 2，固定指定行或者多行

    使用样式去固定

例子：(计算列表数据的平均值，最大值，最小值并固定底部)

1，计算数据的值

protected calcData(data: any) {
        const sums: any = {};
        const max: any = {};
        const min: any = {};
        const columns = this.$refs["coverTable"]?.columns;
        columns.forEach((column: any, index: number) => {
            if (index === 0) {
                sums[column.property] = "平均值";
                max[column.property] = "最大值";
                min[column.property] = "最小值";
                return;
            }
            const values = data.map((item: any) => Number(item[column.property]));
            if (!values.every((value: any) => isNaN(value))) {
                // 总和
                sums[column.property] = values.reduce((prev: any, curr: any) => {
                    const value = Number(curr);
                    if (!isNaN(value)) {
                        return prev + curr;
                    } else {
                        return prev;
                    }
                }, 0);
                // 最大值
                max[column.property] = values.reduce((prev: any, curr: any) => {
                    const value = Number(curr);
                    if (!isNaN(value) && curr > prev) {
                        return curr;
                    } else {
                        return prev;
                    }
                });
                // 最小值
                min[column.property] = values.reduce((prev: any, curr: any) => {
                    const value = Number(curr);
                    if (!isNaN(value) && curr > prev) {
                        return prev;
                    } else {
                        return curr;
                    }
                });
            } else {
                sums[column.property] = "N/A";
                max[column.property] = "N/A";
                min[column.property] = "N/A";
            }
        });

        const average: any = {};
        for (const i in sums) {
            if (!isNaN(sums[i])) {
                average[i] = (sums[i] / data.length).toFixed(3);
            } else {
                average[i] = sums[i];
            }
        }

        if (this.tableData.length > 0) this.tableData.push(average, max, min);
    }

2，对要固定的三行设置class

// 行固定
    tableRowClassName(params: any) {
        const { row, rowIndex } = params;
        row.index = rowIndex;
        // 最后三行固定
        if (rowIndex + 1 === this.tableData.length - 2) {
            return `tr-fixed fixed-row2`;
        } else if (rowIndex + 1 === this.tableData.length - 1) {
            return `tr-fixed fixed-row1`;
        } else if (rowIndex + 1 === this.tableData.length) {
            return `tr-fixed fixed-row`;
        } else {
            return ``;
        }
    }

3, 样式控制

.el-table {
    .tr-fixed{
        display: table-row;
        position: sticky;
        bottom: 0;
        width: 100%;
        td {
            border: 1px solid #f3f5fa;
            background: #fff;
        }
    }
    .fixed-row{
        bottom: 0;
    }
    .fixed-row1{
        bottom: 0.5rem;
    }
    .fixed-row2{
        bottom: 1rem;
    }
}

4，效果