模擬點擊，調用 el-cascader 的公開方法 togglePopperVisible 來展開下拉框

MaterialOut.vue

<script setup lang="ts" name="MaterialOut">
......
import { ElMessage, type ElCascader } from "element-plus";// 級聯組件實例
const cascaderRef = ref<InstanceType<typeof ElCascader> | null>(null);// 記賬
const onJzClick = async () => {if (!ckMaster.value.llPersonId) {ElMessage.error("請選擇領取人員！");// 模擬點擊，調用 el-cascader 的公開方法來展開下拉框cascaderRef.value?.togglePopperVisible(true);return;}
};
......
</script><template>
......<el-cascaderv-elseref="cascaderRef"v-model="llDeptPersonValue":options="departmentUserTreeData":show-all-levels="false"clearable@change="handleLlDeptPersonValueChange" />
......
</template>