HarmonyOS提供了通知功能，即在一個應用的UI界面之外顯示的消息，主要用來提醒用戶有來自該應用中的信息。當應用向系統發出通知時，它將先以圖標的形式顯示在通知欄中，用戶可以下拉通知欄查看通知的詳細信息。

效果如下：

代碼如下：

private void NotificationSlot(){
    NotificationSlot slot = new NotificationSlot("slot_001", "slot_default", NotificationSlot.LEVEL_MIN); // 創建notificationSlot對象
    slot.setDescription("NotificationSlotDescription");
    slot.setEnableVibration(true); // 設置振動提醒
    slot.setEnableLight(true); // 設置開啟呼吸燈提醒
    slot.setLedLightColor(Color.RED.getValue());// 設置呼吸燈的提醒顏色
    try {
        NotificationHelper.addNotificationSlot(slot);
    } catch (RemoteException ex) {
        HiLog.error((HiLogLabel) LABEL, "Exception occurred during addNotificationSlot invocation.");
    }

    int notificationId = 1;
    NotificationRequest request = new NotificationRequest(notificationId);
    request.setSlotId(slot.getId());

    String title = "消息";
    String text = "哈哈哈哈哈哈哈哈";
    NotificationRequest.NotificationNormalContent content = new NotificationRequest.NotificationNormalContent();
    content.setTitle(title)
            .setText(text);
    NotificationRequest.NotificationContent notificationContent = new NotificationRequest.NotificationContent(content);
    request.setContent(notificationContent); // 設置通知的內容

    try {
        NotificationHelper.publishNotification(request);
    } catch (RemoteException ex) {
        HiLog.error((HiLogLabel) LABEL, "Exception occurred during publishNotification invocation.");
    }
}