这样写多选下拉框不显示，怎么实现多选下拉框呢
<fy-dropdown :menuList="menuList">
<fy-dropdown-item v-model="pxVal" dropdownKey="paixu" :options="pxOptions" @change="change1()"></fy-dropdown-item>
<fy-dropdown-item type="column">
<uni-dropdown-item dropdownKey="classify">
<view class="classify">
<view class="h2">分类</view>
<view class="fl flex">
<text v-for="(item,index) in flOptions" @click="flBtn(index)" :class="flIndex==index?'active':''">
{{item.text}}
</text>
</view>
...
</view>
</uni-dropdown-item>
</fy-dropdown-item>
</fy-dropdown>
