vant 动态查询下拉菜单（可用）

动态查询item项

<van-form @submit="onSubmit" ref="formRef">
    <Title title="企业信息" title-line title-size="19" class="ml-[18px] mb-[18px]"></Title>
    <van-cell-group inset class="py-[18px]">
      <div>
        <field-title title="所属企业" class="ml-4"></field-title>
        <van-field
            v-model="model.companyName"
            is-link
            readonly
            name="所属企业"
            placeholder="请选择所属企业"
            @click="showPicker = true"
            :rules="[{ required: true, message: '必填项' }]"
            @input="getCompanyList(model.companyName)"
        />
        <van-popup v-model:show="showPicker" position="bottom" :close-on-click-overlay="false">
          <div class="w-full text-center mt-4">选择企业</div>
          <van-search
              placeholder="输入企业名称"
              v-model="model.companyName"
              @search="onSearch"
              @update:model-value="getCompanyList"
          ></van-search>
          <van-picker
              :columns="options"
              @confirm="onConfirm"
              @cancel="handCancelPickerCompanyInfo"
          >
          </van-picker>
        </van-popup>
      </div>
    </van-cell-group>
    <div style="margin: 16px;">
      <van-button  block type="primary" native-type="submit" :loading="loading" :disabled="loading">
        注册
      </van-button>
    </div>
  </van-form>

  const model = ref({
    companyName: undefined,
    companyCode: undefined,
  })

  const showPicker = ref(false);
  
  const onConfirm = ({selectedOptions}) => {
    model.value.companyName = selectedOptions[0]?.text
    model.value.companyCode = selectedOptions[0]?.value;
    showPicker.value = false;
  };
  function onSearch(value) {
    getCompanyList(value)
  }
  const options = ref<any>([])
  const loading = ref(false)
  const loadingSearch = ref(false)

  function getCompanyList(value: string) {
    if (!value.length) {
      options.value = []
      return
    }
    loadingSearch.value = true
    getEnterpriseOptionApi(value).then((res) => {
      options.value = res.rows.map(item => ({text: item.label, value: item.value}))
      loadingSearch.value = false
    }).catch((err) => {
      loadingSearch.value = false
    })
  }
 function handCancelPickerCompanyInfo() {
   showPicker.value = false
   options.value = []
   model.value.companyName = undefined;
   model.value.companyCode = undefined;
 }