Android通知startForeground的错误通知

Question

我刚刚将我的Android应用targetSdkVersion升级到28。

我正在使用以下代码在Android应用中创建通知：

@SuppressLint("NewApi")
private void handleCommand(Intent intent) {
    if (ACTION_FOREGROUND.equals(intent.getAction())) {

        final YouTubeFile ytf = PlayerDataManager.getInstance().getYouTubeFile();
        String nowPlayingTitle = "";
        if (ytf != null) {
            nowPlayingTitle = ytf.getTitle();
        }

        String ns = Context.NOTIFICATION_SERVICE;
        NotificationManager mNotificationManager = (NotificationManager) getSystemService(ns);

        long when = System.currentTimeMillis();

        final RemoteViews contentView = new RemoteViews(getPackageName(), R.layout.itube_notification);
        ReceiverNotification.s_RemoteView = contentView;

        if (ytf != null) {
            try {
                Bitmap bmp = ImageLoader.getInstance().loadImageSync(ytf.getImageUrl());
                contentView.setImageViewBitmap(R.id.icon_fav_notification, bmp);

            } catch (Exception e) {
                Logger.e(e);
            }
        }

        contentView.setTextViewText(R.id.toptext, nowPlayingTitle);

        Intent rewindIntent = new Intent(this, ReceiverNotification.class);
        rewindIntent.putExtra("ACTION", 0);
        rewindIntent.setAction("REWIND");
        PendingIntent pendingIntent1 = PendingIntent.getBroadcast(getApplicationContext(), 000, rewindIntent,
                FLAG_UPDATE_CURRENT);
        contentView.setOnClickPendingIntent(R.id.imageButtonPlayLast, pendingIntent1);

        Intent playIntent = new Intent(this, ReceiverNotification.class);
        playIntent.putExtra("ACTION", 1);
        playIntent.setAction("PLAY");
        PendingIntent pendingIntent2 = PendingIntent
                .getBroadcast(getApplicationContext(), 111, playIntent, FLAG_UPDATE_CURRENT);
        contentView.setOnClickPendingIntent(R.id.imageButtonPlay, pendingIntent2);

        Intent forwardIntent = new Intent(this, ReceiverNotification.class);
        forwardIntent.putExtra("ACTION", 2);
        forwardIntent.setAction("FORWARD");
        PendingIntent pendingIntent3 = PendingIntent.getBroadcast(getApplicationContext(), 222, forwardIntent,
                FLAG_UPDATE_CURRENT);
        contentView.setOnClickPendingIntent(R.id.imageButtonPlayNext, pendingIntent3);

        Intent exitIntent = new Intent(this, ReceiverNotification.class);
        exitIntent.putExtra("ACTION", 3);
        exitIntent.setAction("EXIT");
        PendingIntent pendingIntent4 = PendingIntent
                .getBroadcast(getApplicationContext(), 333, exitIntent, FLAG_UPDATE_CURRENT);
        contentView.setOnClickPendingIntent(R.id.exit_icon, pendingIntent4);
        contentView.setViewVisibility(R.id.exit_icon, View.VISIBLE);

        if (PlayerManager.getInstance().isPlaying()) {
            contentView.setImageViewResource(R.id.imageButtonPlay, R.drawable.ic_action_av_pause_light);

        } else {
            contentView.setImageViewResource(R.id.imageButtonPlay, R.drawable.ic_action_av_play_light);
        }

        Intent notificationIntent = new Intent(this, MainActivity.class);
        PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);

        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            createNotificationChannel();

        }

        NotificationCompat.Builder builder = new NotificationCompat.Builder(GuiManager.getInstance().getMainActivity(), CHANNEL_ID);
        builder.setContentIntent(contentIntent)
                .setSmallIcon(R.drawable.ic_launcher)
                .setWhen(when)
                .setAutoCancel(false).setVibrate(new long[]{0L})
                .setCustomContentView(contentView);

        if (Build.VERSION.SDK_INT >= 21) {
            builder.setVisibility(Notification.VISIBILITY_PUBLIC);
        }

        if(Build.VERSION.SDK_INT < Build.VERSION_CODES.O){
            builder.setPriority(Notification.PRIORITY_DEFAULT);

        }

        Notification notification = builder.build();

        notification.flags |= Notification.FLAG_NO_CLEAR;
        notification.defaults |= Notification.DEFAULT_LIGHTS;

        if (mNotificationManager != null) {
                mNotificationManager.notify(NOTIFICATION_ID, notification);
        }
        startForeground(NOTIFICATION_ID, new Notification());


    } else if (ACTION_BACKGROUND.equals(intent.getAction())) {
        stopForegroundCompat(R.string.notification_service_started);
    }
}

private void createNotificationChannel() {
    // Create the NotificationChannel, but only on API 26+ because
    // the NotificationChannel class is new and not in the support library
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        CharSequence name = getString(R.string.notification_channel_title);
        String description = getString(R.string.notification_channel_description);
            int importance = NotificationManager.IMPORTANCE_LOW;
        NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
        channel.setDescription(description);
        // Register the channel with the system; you can't change the importance
        // or other notification behaviors after this
        NotificationManager notificationManager = getSystemService(NotificationManager.class);
        if (notificationManager != null) {
            notificationManager.createNotificationChannel(channel);
        }
    }
}

当我运行它时，我得到这个Exception：

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.****.dev, PID: 17029
android.app.RemoteServiceException: Bad notification for startForeground: java.lang.RuntimeException: invalid channel for service notification: Notification(channel=null pri=0 contentView=null vibrate=null sound=null defaults=0x0 flags=0x40 color=0x00000000 vis=PRIVATE semFlags=0x0 semPriority=0 semMissedCount=0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1872)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:214)
    at android.app.ActivityThread.main(ActivityThread.java:7050)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:965)

我已经将其添加到应用清单中

<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />