1.在</a-table>下方加如下代码

<div>数据总条数：{{tableData.length}}&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp

        <template>A列合计：{{sum}}</template>

</div>

注：tableData为<a-table>标签中 :dataSource="tableData"的值

2.引入bignumber.js，对小数计算不精确多小数位进行处理

import BigNumber from 'bignumber.js'

3.定义sum

const sum = ref(0)

4.定义计算的函数

const sumFunction = () => {

        sum.value = tableData.value.reduce((acc, item) => {

                const A = Number(item.A) || 0;

                return acc.plus(new BigNumber(A))

        }, new BigNumber(0)).toNumber()

}