模拟点击，调用 el-cascader 的公开方法 togglePopperVisible 来展开下拉框

MaterialOut.vue

<script setup lang="ts" name="MaterialOut">
......
import { ElMessage, type ElCascader } from "element-plus";// 级联组件实例
const cascaderRef = ref<InstanceType<typeof ElCascader> | null>(null);// 记账
const onJzClick = async () => {if (!ckMaster.value.llPersonId) {ElMessage.error("请选择领取人员！");// 模拟点击，调用 el-cascader 的公开方法来展开下拉框cascaderRef.value?.togglePopperVisible(true);return;}
};
......
</script><template>
......<el-cascaderv-elseref="cascaderRef"v-model="llDeptPersonValue":options="departmentUserTreeData":show-all-levels="false"clearable@change="handleLlDeptPersonValueChange" />
......
</template>