element 循环生成多个可多选表格，修改表格数据的选中状态

Question

循环数据，生成多个可多选的表格，然后向后台请求数据，得到用户之前选中的数据，然后修改每个表格数据的选中状态，但是修改状态的时候并没有生效

<el-table v-for="(type,index) in formData" :key="index" :data="type.data" ref="multipleTable" style="width: 100%" @selection-change="handleSelectionChange($event,index)">
    <el-table-column type="selection" :selectable='checkboxInit' width="55"></el-table-column>
    <el-table-column label="审核状态" min-width="120">
        <template slot-scope="scope">
            <span v-if="scope.row.status == '26'" class="text-muted">待审核</span>
            <span v-if="scope.row.status == '28'" class="text-success">通过审核</span>
            <span v-if="scope.row.status == '27'" class="text-danger">退回材料</span>
            <span v-if="scope.row.status=='29'" class="text-gray-dark">无需审核</span>
        </template>
    </el-table-column>
    <el-table-column prop="title" label="标题" show-overflow-tooltip min-width="120"> </el-table-column>
    <el-table-column prop="add_time" label="提交日期" min-width="120" ></el-table-column>
    <el-table-column label="认证状态" min-width="120">
        <template slot-scope="scope">
            <span v-if="scope.row.status != '28'" class="text-muted">未认证</span>
            <span v-if="scope.row.status == '28'" class="text-success">已认证</span>
        </template>
    </el-table-column>
</el-table>

//循环后台返回用户选中的数据，修改表格选中状态
var readData = response.data.data;
for(var i in readData){
    this.check[i].arr = readData[i];
    for(var j in readData[i].data){
        this.$refs.multipleTable[i].toggleRowSelection(readData[i].data[j],true);
    }
}