element-ui的table表格通过子表数据，进行展示左侧展开箭头

1：设置el-table的class

<el-table :data="flowTableList" :row-class-name="getRowClass">
        <el-table-column label="当前环节" prop="currentTacheName">
        </el-table-column>
      </el-table>

2：js设置getRowClass方法处理

public getRowClass(scope: any, index: string) {
    if (!scope.row.sonItemDTOList || scope.row.sonItemDTOList.length <= 0) {
      return 'hide-row';
    } else {
      return 'show-row';
    }
  }

3： style定义hide-row

::v-deep {
  .hide-row {
    .el-table__expand-column {
      visibility: hidden !important;
    }
  }
}