Android O reporting notification not posted to channel - but it is

Question

Couple Android O notification questions:

1) I have created a Notification Channel (see below), am calling the builder with .setChannelId() (passing in the name of th

Answer 1

You gotta create a channel before.

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.channel_name);
            String description = getString(R.string.channel_description);
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            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);
            notificationManager.createNotificationChannel(channel);
        }
}

public void notifyThis(String title, String message) {
        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setSmallIcon(R.drawable.green_circle)
                .setContentTitle(title)
                .setContentText(message)
                .setPriority(NotificationCompat.PRIORITY_DEFAULT);

        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);

        // notificationId is a unique int for each notification that you must define
        notificationManager.notify(0, mBuilder.build());
}

Finally you call this method:

createNotificationChannel();
notifyThis("My notification", "Hello World!");

Answer 2

create a notification using following code :

    Notification notification = new Notification.Builder(MainActivity.this)
              .setContentTitle("New Message")
                        .setContentText("You've received new messages.")
                        .setSmallIcon(R.mipmap.ic_launcher)
                        .setChannelId(channelId)
                        .build();

not using :

Notification notification = new NotificationCompat.Builder(MainActivity.this)
                    .setContentTitle("Some Message")
                    .setContentText("You've received new messages!")
                    .setSmallIcon(R.mipmap.ic_launcher)
                    .setChannel(channelId)
                    .build();

Answer 3

I would also like to add that you will receive this error if you're using Build tools v26+:

app/build.grade:

compileSdkVersion 26
buildToolsVersion "26.0.2"

defaultConfig {
    targetSdkVersion 26

Downgrading to lowest version should work fine.

Answer 4

I was facing the same problem. It got resolved by creating a NotificationChannel and adding that newly created channel with the notification manager.

Answer 5

First create the notification channel:

 public static final String NOTIFICATION_CHANNEL_ID = "4565";
//Notification Channel
        CharSequence channelName = NOTIFICATION_CHANNEL_NAME;
        int importance = NotificationManager.IMPORTANCE_LOW;
        NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, NOTIFICATION_CHANNEL_NAME, importance);
        notificationChannel.enableLights(true);
        notificationChannel.setLightColor(Color.RED);
        notificationChannel.enableVibration(true);
        notificationChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});


NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.createNotificationChannel(notificationChannel);

then use the channel id in the constructor:

final NotificationCompat.Builder builder = new NotificationCompat.Builder(context, NOTIFICATION_CHANNEL_ID)
                .setDefaults(Notification.DEFAULT_ALL)
                .setSmallIcon(R.drawable.ic_timers)
                .setVibrate(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400})
                .setSound(null)
                .setChannelId(NOTIFICATION_CHANNEL_ID)
                .setContent(contentView)
                .setPriority(NotificationCompat.PRIORITY_DEFAULT)
                .setLargeIcon(picture)
                .setTicker(sTimer)
                .setContentIntent(pendingIntent)
                .setAutoCancel(false);

Answer 6

You have to create a NotificationChannel first

val notificationChannel = NotificationChannel("channelId", "channelName", NotificationManager.IMPORTANCE_DEFAULT)
notificationManager.createNotificationChannel(notificationChannel);

This is the only way to show notification for API 26+