final String CHANNEL_ID = "channel_id_1";
final String CHANNEL_NAME = "channel_name_1";

NotificationManager mManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
Notification.Builder builder = null;


if(Build.VERSION.SDK_INT < Build.VERSION_CODES.O){
        builder = new Notification.Builder(this
 
);
}else{
        NotificationChannel notificationChannel = new NotificationChannel(Config.CHANNEL_ID,
                    Config.CHANNEL_NAME, NotificationManager.IMPORTANCE_HIGH);
            //如果這裏用IMPORTANCE_NOENE就需要在系統的設置裏面開啟渠道，
            //通知才能正常彈出
            
    mManager.createNotificationChannel(notificationChannel);
            builder 
 
= new Notification.Builder(this,Config.CHANNEL_ID);
}

notification = builder.build();
mManager.notify(555, notification);

android 通知（android 8.0可用）