java - android通知横幅不显示

Question

出于某种原因，当我在我的应用程序中发出通知时，它会振动并发出噪音，但手机顶部没有出现横幅。是否需要特定的命令才能让它执行此操作？

public Notification getNotification(String message) {
        Intent intent = new Intent(serviceContext,     NotificationGenerator.class); //not sure how
        // this class i pass matters
        PendingIntent pi = PendingIntent.getActivity(serviceContext, 0, intent, 0);
        NotificationCompat.Builder builder = new     NotificationCompat.Builder(serviceContext)
            .setContentTitle(message)
            .setContentText(message)
            .setSmallIcon(R.drawable.dominos_icon)
            .setContentIntent(pi);
        Notification n = builder.build();
        n.defaults = Notification.DEFAULT_ALL;
        return n;
    }

Answer 1

添加以下行后，您的代码将正常运行:

NotificationManager n_mngr = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
n_mngr.notify(NOTIF_ID, n);