I am trying to expand notification if text is long by below code.
NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
.setSmallIcon(getNotificationIcon())
.setColor(ContextCompat.getColor(getApplicationContext(), R.color.colorPrimary))
.setContentTitle(getString(R.string.app_name))
.setAutoCancel(true)
.setSound(defaultSoundUri)
.setStyle(new NotificationCompat.BigTextStyle().bigText(messageBody))
.setContentIntent(pendingIntent);
NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(0, notificationBuilder.build());
but it shows single line notification and cannot expand it. My testing device is the Marshmallow.