在 Vue 3 中的 Composition API 中，$refs 并不直接可用于 setup 函数。这是因为 $refs 是 Vue 2 的实例属性，而在 Vue 3 中，setup 函数是与模板实例分离的，不再使用实例属性。

实际工作中确实有需求，在setup 函数使用$refs，下面有两种方法。

方案

方案一：getCurrentInstance

<template>
    <el-table ref="multipleTableRef" :data="tableData" style="width: 100%" @selection-change="handleSelectionChange">
        <el-table-column type="selection" width="55" />
        <el-table-column label="Date" width="120">
            <template #default="scope">{{ scope.row.date }}</template>
        </el-table-column>
        <el-table-column property="name" label="Name" width="120" />
        <el-table-column property="address" label="Address" show-overflow-tooltip />
    </el-table>
    <div style="margin-top: 20px">
        <el-button @click="toggleSelection([tableData[1], tableData[2]])">Toggle selection status of second and third
            rows</el-button>
        <el-button @click="toggleSelection()">Clear selection</el-button>
    </div>
</template>

<script setup>
import { ref, getCurrentInstance } from 'vue'
const tableData = [
    {
        date: '2016-05-03',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-02',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-04',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-01',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-08',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-06',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-07',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
]

const multipleSelection = ref([])
const handleSelectionChange = (val) => {
    multipleSelection.value = val
}

const {proxy} = getCurrentInstance();
const toggleSelection = (rows) => {
    if (rows) {
        rows.forEach((row) => {
            proxy.$refs.multipleTableRef.toggleRowSelection(row, undefined)
        })
    } else {
        proxy.$refs.multipleTableRef.clearSelection()
    }
}
</script>

方案二： ref

<template>
    <el-table ref="multipleTableRef" :data="tableData" style="width: 100%" @selection-change="handleSelectionChange">
        <el-table-column type="selection" width="55" />
        <el-table-column label="Date" width="120">
            <template #default="scope">{{ scope.row.date }}</template>
        </el-table-column>
        <el-table-column property="name" label="Name" width="120" />
        <el-table-column property="address" label="Address" show-overflow-tooltip />
    </el-table>
    <div style="margin-top: 20px">
        <el-button @click="toggleSelection([tableData[1], tableData[2]])">Toggle selection status of second and third
            rows</el-button>
        <el-button @click="toggleSelection()">Clear selection</el-button>
    </div>
</template>

<script setup>
import { ref } from 'vue'
const tableData = [
    {
        date: '2016-05-03',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-02',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-04',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-01',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-08',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-06',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
    {
        date: '2016-05-07',
        name: 'Tom',
        address: 'No. 189, Grove St, Los Angeles',
    },
]
const multipleTableRef = ref()
const multipleSelection = ref([])
const handleSelectionChange = (val) => {
    multipleSelection.value = val
}
const toggleSelection = (rows) => {
    if (rows) {
        rows.forEach((row) => {
            multipleTableRef.value.toggleRowSelection(row, undefined)
        })
    } else {
        multipleTableRef.value.clearSelection()
    }
}

</script>

在这个示例中，multipleTableRef 是一个通过 ref 创建的响应式变量，用于存储对 el-table 元素的引用。

结果显示