通知チャンネルIDとは何ですか？通知はAPIで機能しません27

Question

プロジェクトのapiターゲットを27に更新し、すべての通知を無効にしました。
API 26と27の通知の違いは何ですか？

 Notification notif = new NotificationCompat.Builder(this) 
       .setContentTitle(getString(R.string.app_name)) 
       .setContentText(message) 
       .setSmallIcon(R.mipmap.ic_launcher) 
       .setContentIntent(pIntent) 
       .setSound(alarmSound) 
       .setAutoCancel(true).build(); 
     notif.ledARGB = 0xFFff0000; 
     notif.flags = Notification.FLAG_SHOW_LIGHTS; 
     notif.ledOnMS = 100; 
     notif.ledOffMS = 100; 

     NotificationManager notificationCompatManager = 
       (NotificationManager) getSystemService(NOTIFICATION_SERVICE); 
     notificationCompatManager.notify(0, notif); 

Answer 1

あなたは、API -27と27の両方に通知を表示するには、このメソッドを使用することができます：最初の分でこの質問を見た

void showNotification(String title, String content) { 
    NotificationManager mNotificationManager = 
      (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE); 
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) { 
     NotificationChannel channel = new NotificationChannel("default", 
       "YOUR_CHANNEL_NAME", 
       NotificationManager.IMPORTANCE_DEFAULT); 
     channel.setDescription("YOUR_NOTIFICATION_CHANNEL_DISCRIPTION"); 
     mNotificationManager.createNotificationChannel(channel); 
    } 
    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext(), "default") 
      .setSmallIcon(R.mipmap.ic_launcher) // notification icon 
      .setContentTitle(title) // title for notification 
      .setContentText(content)// message for notification 
      .setSound(alarmSound) // set alarm sound for notification 
      .setAutoCancel(true); // clear notification after click 
    Intent intent = new Intent(getApplicationContext(), MainActivity_.class); 
    PendingIntent pi = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT); 
    mBuilder.setContentIntent(pi); 
    mNotificationManager.notify(0, mBuilder.build()); 
}