iview 表格多选框的选中事件

<form-item>
<td>
    <checkbox-group v-model="userInfoarr.itemInvolve">
        <checkbox :key="involve.key" :label="involve.key">
         <span style="margin-right: 0px;"></span>
        </checkbox>
    </checkbox-group>
</td>
</form-item>