Benachrichtigung wird in Oreo nicht angezeigt

Normal Notification Builder zeigt keine Benachrichtigungen unter Android O an.

Wie kann ich eine Benachrichtigung auf Android 8 Oreo anzeigen?

Gibt es einen neuen Code zum Anzeigen der Benachrichtigung auf Android O?

In Android O ist es ein Muss, einen Kanal mit Ihrem Notification Builder zu verwenden

Unten ist ein Beispielcode:

// Sets an ID for the notification, so it can be updated.
int notifyID = 1; 
String CHANNEL_ID = "my_channel_01";// The id of the channel. 
CharSequence name = getString(R.string.channel_name);// The user-visible name of the channel.
int importance = NotificationManager.IMPORTANCE_HIGH;
NotificationChannel mChannel = new NotificationChannel(CHANNEL_ID, name, importance);
// Create a notification and set the notification channel.
Notification notification = new Notification.Builder(MainActivity.this)
            .setContentTitle("New Message")
            .setContentText("You've received new messages.")
            .setSmallIcon(R.drawable.ic_notify_status)
            .setChannelId(CHANNEL_ID)
            .build();

Oder mit Handhabungskompatibilität durch:

NotificationCompat notification =
        new NotificationCompat.Builder(this)
        .setSmallIcon(R.drawable.notification_icon)
        .setContentTitle("My notification")
        .setContentText("Hello World!")
        .setChannelId(CHANNEL_ID).build();



NotificationManager mNotificationManager =
            (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
 mNotificationManager.createNotificationChannel(mChannel);

// Issue the notification.
mNotificationManager.notify(notifyID , notification);

oder wenn Sie eine einfache Lösung wünschen, verwenden Sie den folgenden Code:

NotificationManager mNotificationManager =
            (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
       mNotificationManager.createNotificationChannel(mChannel);
    }

Updates: NotificationCompat.Builder-Referenz

NotificationCompat.Builder(Context context)

Dieser Konstruktor war in API-Version 26.0.0 veraltet, daher sollten Sie ihn verwenden

Builder(Context context, String channelId)

Also keine Notwendigkeit setChannelIdmit dem neuen Konstruktor.

Und Sie sollten die neueste AppCompat-Bibliothek verwenden, die derzeit 26.0.2 ist

compile "com.android.support:appcompat-v7:26.0.+"

Quelle aus Android Developers Channel auf Youtube

Sie können auch die offiziellen Android-Dokumente überprüfen

Hier poste ich eine schnelle Lösungsfunktion mit Absichtsbehandlung

public void showNotification(Context context, String title, String body, Intent intent) {
    NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

    int notificationId = 1;
    String channelId = "channel-01";
    String channelName = "Channel Name";
    int importance = NotificationManager.IMPORTANCE_HIGH;

    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
        NotificationChannel mChannel = new NotificationChannel(
                channelId, channelName, importance);
        notificationManager.createNotificationChannel(mChannel);
    }

    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context, channelId)
            .setSmallIcon(R.mipmap.ic_launcher)
            .setContentTitle(title)
            .setContentText(body);

    TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
    stackBuilder.addNextIntent(intent);
    PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(
            0,
            PendingIntent.FLAG_UPDATE_CURRENT
    );
    mBuilder.setContentIntent(resultPendingIntent);

    notificationManager.notify(notificationId, mBuilder.build());
}

Zusätzlich zu dieser Antwort müssen Sie den Benachrichtigungskanal erstellen, bevor er verwendet werden kann.

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

      /* Create or update. */
      NotificationChannel channel = new NotificationChannel("my_channel_01",
          "Channel human readable title", 
          NotificationManager.IMPORTANCE_DEFAULT);
      mNotificationManager.createNotificationChannel(channel);
  }

Außerdem müssen Sie Kanäle nur verwenden, wenn Ihre targetSdkVersion 26 oder höher ist.

Wenn Sie NotificationCompat.Builder verwenden, müssen Sie auch auf die Beta-Version der Support-Bibliothek aktualisieren: https://developer.android.com/topic/libraries/support-library/revisions.html#26-0-0- Beta2 (um setChannelIdden Compat Builder aufrufen zu können).

Seien Sie vorsichtig, da dieses Bibliotheksupdate minSdkLevel auf 14 erhöht.

public class MyFirebaseMessagingServices extends FirebaseMessagingService {
    private NotificationChannel mChannel;
    private NotificationManager notifManager;
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        if (remoteMessage.getData().size() > 0) {
            try {
                JSONObject jsonObject = new JSONObject(remoteMessage.getData());
                displayCustomNotificationForOrders(jsonObject.getString("title"), jsonObject.getString("description"));
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }

    private void displayCustomNotificationForOrders(String title, String description) {
        if (notifManager == null) {
            notifManager = (NotificationManager) getSystemService
                    (Context.NOTIFICATION_SERVICE);
        }
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationCompat.Builder builder;
            Intent intent = new Intent(this, Dashboard.class);
            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            PendingIntent pendingIntent;
            int importance = NotificationManager.IMPORTANCE_HIGH;
            if (mChannel == null) {
                mChannel = new NotificationChannel
                        ("0", title, importance);
                mChannel.setDescription(description);
                mChannel.enableVibration(true);
                notifManager.createNotificationChannel(mChannel);
            }
            builder = new NotificationCompat.Builder(this, "0");

            intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP |
                    Intent.FLAG_ACTIVITY_SINGLE_TOP);
            pendingIntent = PendingIntent.getActivity(this, 1251, intent, PendingIntent.FLAG_ONE_SHOT);
            builder.setContentTitle(title)  
                    .setSmallIcon(getNotificationIcon()) // required
                    .setContentText(description)  // required
                    .setDefaults(Notification.DEFAULT_ALL)
                    .setAutoCancel(true)
                    .setLargeIcon(BitmapFactory.decodeResource
                            (getResources(), R.mipmap.logo))
                    .setBadgeIconType(R.mipmap.logo)
                    .setContentIntent(pendingIntent)
                    .setSound(RingtoneManager.getDefaultUri
                            (RingtoneManager.TYPE_NOTIFICATION));
            Notification notification = builder.build();
            notifManager.notify(0, notification);
        } else {

            Intent intent = new Intent(this, Dashboard.class);
            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            PendingIntent pendingIntent = null;

            pendingIntent = PendingIntent.getActivity(this, 1251, intent, PendingIntent.FLAG_ONE_SHOT);

            Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
            NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
                    .setContentTitle(title)
                    .setContentText(description)
                    .setAutoCancel(true)
                    .setColor(ContextCompat.getColor(getBaseContext(), R.color.colorPrimary))
                    .setSound(defaultSoundUri)
                    .setSmallIcon(getNotificationIcon())
                    .setContentIntent(pendingIntent)
                    .setStyle(new NotificationCompat.BigTextStyle().setBigContentTitle(title).bigText(description));

            NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            notificationManager.notify(1251, notificationBuilder.build());
        }
    }

    private int getNotificationIcon() {
        boolean useWhiteIcon = (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP);
        return useWhiteIcon ? R.mipmap.logo : R.mipmap.logo;
    }
}

Wenn Sie die Push-Benachrichtigung in der SDK-Version 26+ nicht erhalten können?

Ihre Lösung ist hier:

public static void showNotification(Context context, String title, String messageBody) {

        boolean isLoggedIn = SessionManager.getInstance().isLoggedIn();
        Log.e(TAG, "User logged in state: " + isLoggedIn);

        Intent intent = null;
        if (isLoggedIn) {
            //goto notification screen
            intent = new Intent(context, MainActivity.class);
            intent.putExtra(Extras.EXTRA_JUMP_TO, DrawerItems.ITEM_NOTIFICATION);
        } else {
            //goto login screen
            intent = new Intent(context, LandingActivity.class);
        }

        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0 /* Request code */, intent, PendingIntent.FLAG_ONE_SHOT);

        //Uri defaultSoundUri= RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        //Bitmap largeIcon = BitmapFactory.decodeResource(getResources(), R.drawable.ic_app_notification_icon);

        String channel_id = createNotificationChannel(context);

        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(context, channel_id)
                .setContentTitle(title)
                .setContentText(messageBody)
                .setStyle(new NotificationCompat.BigTextStyle().bigText(messageBody))
                /*.setLargeIcon(largeIcon)*/
                .setSmallIcon(R.drawable.app_logo_color) //needs white icon with transparent BG (For all platforms)
                .setColor(ContextCompat.getColor(context, R.color.colorPrimaryDark))
                .setVibrate(new long[]{1000, 1000})
                .setSound(Settings.System.DEFAULT_NOTIFICATION_URI)
                .setContentIntent(pendingIntent)
                .setPriority(Notification.PRIORITY_HIGH)
                .setAutoCancel(true);

        NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify((int) ((new Date(System.currentTimeMillis()).getTime() / 1000L) % Integer.MAX_VALUE) /* ID of notification */, notificationBuilder.build());
    }

public static String createNotificationChannel(Context context) {

        // NotificationChannels are required for Notifications on O (API 26) and above.
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

            // The id of the channel.
            String channelId = "Channel_id";

            // The user-visible name of the channel.
            CharSequence channelName = "Application_name";
            // The user-visible description of the channel.
            String channelDescription = "Application_name Alert";
            int channelImportance = NotificationManager.IMPORTANCE_DEFAULT;
            boolean channelEnableVibrate = true;
//            int channelLockscreenVisibility = Notification.;

            // Initializes NotificationChannel.
            NotificationChannel notificationChannel = new NotificationChannel(channelId, channelName, channelImportance);
            notificationChannel.setDescription(channelDescription);
            notificationChannel.enableVibration(channelEnableVibrate);
//            notificationChannel.setLockscreenVisibility(channelLockscreenVisibility);

            // Adds NotificationChannel to system. Attempting to create an existing notification
            // channel with its original values performs no operation, so it's safe to perform the
            // below sequence.
            NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
            assert notificationManager != null;
            notificationManager.createNotificationChannel(notificationChannel);

            return channelId;
        } else {
            // Returns null for pre-O (26) devices.
            return null;
        }
    }

NotificationCompat.Builder notificationBuilder = neuer NotificationCompat.Builder (Kontext, Kanal-ID)

-> Hier erhalten Sie eine Push-Benachrichtigung mit channel_id auf Ihrem Gerät eine SDK-Version ab 26 verwenden.

-> Weil die NotificationCompat.Builder(context) Methode jetzt veraltet ist, verwenden Sie eine aktualisierte Version mit zwei Parametern, einer ist Kontext, der andere ist channel_id.

-> NotificationCompat.Builder(context, channel_id) aktualisierte Methode. Versuch es.

-> In der SDK-Version 26+ des Geräts erstellen Sie jedes Mal channel_id.

Verwenden Sie diese Klasse für die Android 8-Benachrichtigung

public class NotificationHelper {

private Context mContext;
private NotificationManager mNotificationManager;
private NotificationCompat.Builder mBuilder;
public static final String NOTIFICATION_CHANNEL_ID = "10001";

public NotificationHelper(Context context) {
    mContext = context;
}

/**
 * Create and push the notification 
 */
public void createNotification(String title, String message)
{    
    /**Creates an explicit intent for an Activity in your app**/
    Intent resultIntent = new Intent(mContext , SomeOtherActivity.class);
    resultIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    PendingIntent resultPendingIntent = PendingIntent.getActivity(mContext,
            0 /* Request code */, resultIntent,
            PendingIntent.FLAG_UPDATE_CURRENT);

    mBuilder = new NotificationCompat.Builder(mContext);
    mBuilder.setSmallIcon(R.mipmap.ic_launcher);
    mBuilder.setContentTitle(title)
            .setContentText(message)
            .setAutoCancel(false)
            .setSound(Settings.System.DEFAULT_NOTIFICATION_URI)
            .setContentIntent(resultPendingIntent);

    mNotificationManager = (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);

    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O)
    {
        int importance = NotificationManager.IMPORTANCE_HIGH;
        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});
        assert mNotificationManager != null;
        mBuilder.setChannelId(NOTIFICATION_CHANNEL_ID);
        mNotificationManager.createNotificationChannel(notificationChannel);
    }
    assert mNotificationManager != null;
    mNotificationManager.notify(0 /* Request Code */, mBuilder.build());
  }
}

Versuchen Sie diesen Code:

public class FirebaseMessagingServices extends com.google.firebase.messaging.FirebaseMessagingService {
    private static final String TAG = "MY Channel";
    Bitmap bitmap;

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);
        Utility.printMessage(remoteMessage.getNotification().getBody());

        // Check if message contains a data payload.
        if (remoteMessage.getData().size() > 0) {
            Log.d(TAG, "Message data payload: " + remoteMessage.getData());

            String title = remoteMessage.getData().get("title");
            String body = remoteMessage.getData().get("body");
            String message = remoteMessage.getData().get("message");
            String imageUri = remoteMessage.getData().get("image");
            String msg_id = remoteMessage.getData().get("msg-id");
          

            Log.d(TAG, "1: " + title);
            Log.d(TAG, "2: " + body);
            Log.d(TAG, "3: " + message);
            Log.d(TAG, "4: " + imageUri);
          

            if (imageUri != null)
                bitmap = getBitmapfromUrl(imageUri);

            }

            sendNotification(message, bitmap, title, msg_id);
                    
        }


    }

    private void sendNotification(String message, Bitmap image, String title,String msg_id) {
        int notifyID = 0;
        try {
            notifyID = Integer.parseInt(msg_id);
        } catch (NumberFormatException e) {
            e.printStackTrace();
        }

        String CHANNEL_ID = "my_channel_01";            // The id of the channel.
        Intent intent = new Intent(this, HomeActivity.class);
        intent.putExtra("title", title);
        intent.putExtra("message", message);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);


        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0 /* Request code */, intent,
                PendingIntent.FLAG_ONE_SHOT);

        Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, "01")
                .setContentTitle(title)
                .setSmallIcon(R.mipmap.ic_notification)
                .setStyle(new NotificationCompat.BigTextStyle()
                        .bigText(message))
                .setContentText(message)
                .setAutoCancel(true)
                .setSound(defaultSoundUri)
                .setChannelId(CHANNEL_ID)
                .setContentIntent(pendingIntent);

        if (image != null) {
            notificationBuilder.setStyle(new NotificationCompat.BigPictureStyle()   //Set the Image in Big picture Style with text.
                    .bigPicture(image)
                    .setSummaryText(message)
                    .bigLargeIcon(null));
        }


        NotificationManager notificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {       // For Oreo and greater than it, we required Notification Channel.
           CharSequence name = "My New Channel";                   // The user-visible name of the channel.
            int importance = NotificationManager.IMPORTANCE_HIGH;

            NotificationChannel channel = new NotificationChannel(CHANNEL_ID,name, importance); //Create Notification Channel
            notificationManager.createNotificationChannel(channel);
        }

        notificationManager.notify(notifyID /* ID of notification */, notificationBuilder.build());
    }

    public Bitmap getBitmapfromUrl(String imageUrl) {     //This method returns the Bitmap from Url;
        try {
            URL url = new URL(imageUrl);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            Bitmap bitmap = BitmapFactory.decodeStream(input);
            return bitmap;

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return null;

        }

    }

}

Android Notification Demo App für Android O sowie niedrigere API-Versionen. Hier ist die beste Demo-App für GitHub-Demo 1 und GitHub-Demo 2 .

Dies ist ein Fehler in der Firebase-API-Version 11.8.0. Wenn Sie also die API-Version reduzieren, tritt dieses Problem nicht auf.

Ich hatte das gleiche Problem mit Oreo und stellte fest, dass der Kanal die ursprüngliche Wichtigkeitsstufe beibehält, wenn Sie Ihren Kanal zuerst mit NotificationManager.IMPORTANCE_NONE erstellen und später aktualisieren.

Dies wird durch die Google Notification-Schulungsdokumentation gesichert, in der Folgendes angegeben ist:

Nachdem Sie einen Benachrichtigungskanal erstellt haben, können Sie das Benachrichtigungsverhalten nicht mehr ändern. Der Benutzer hat zu diesem Zeitpunkt die vollständige Kontrolle.

Durch Entfernen und erneutes Installieren der App können Sie das Kanalverhalten zurücksetzen.

Vermeiden Sie am besten die Verwendung von IMPORTANCE_NONE, es sei denn, Sie möchten die Benachrichtigungen für diesen Kanal unterdrücken, dh stille Benachrichtigungen verwenden.

So machen Sie es

private fun sendNotification() {
    val notificationId = 100
    val chanelid = "chanelid"
    val intent = Intent(this, MainActivity::class.java)
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK)
    val pendingIntent = PendingIntent.getActivity(this, 0, intent, 0)
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { // you must create a notification channel for API 26 and Above
        val name = "my channel"
        val description = "channel description"
        val importance = NotificationManager.IMPORTANCE_DEFAULT
        val channel = NotificationChannel(chanelid, name, importance);
        channel.setDescription(description);
        // Register the channel with the system; you can't change the importance
        // or other notification behaviors after this
        val notificationManager = getSystemService(NotificationManager::class.java)
        notificationManager.createNotificationChannel(channel)
    }

    val mBuilder = NotificationCompat.Builder(this, chanelid)
            .setSmallIcon(R.drawable.ic_notification)
            .setContentTitle("Want to Open My App?")
            .setContentText("Open my app and see good things")
            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
            .setContentIntent(pendingIntent)
            .setAutoCancel(true) // cancel the notification when clicked
            .addAction(R.drawable.ic_check, "YES", pendingIntent) //add a btn to the Notification with a corresponding intent

    val notificationManager = NotificationManagerCompat.from(this);
    notificationManager.notify(notificationId, mBuilder.build());
}

Lesen Sie das vollständige Tutorial unter => https://developer.android.com/training/notify-user/build-notification

CHANNEL_IDVersuchen Sie diesen Code in NotificationChannel und Notification.Builder identisch:

String CHANNEL_ID = "my_channel_01";
NotificationChannel channel = new NotificationChannel(CHANNEL_ID, "Solveta Unread", NotificationManager.IMPORTANCE_DEFAULT);


Notification.Builder notification = new Notification.Builder(getApplicationContext(), CHANNEL_ID);

Nun, in meinem Fall habe ich Android 8.1.0 und die Modellnummer vivo1811 und ich habe es mit allen oben genannten Lösungen versucht, aber nichts funktioniert.

Endlich habe ich an den Firebase-Support geschrieben. Beim weiteren Debuggen wurde Folgendes angezeigt: "Übertragung an gestoppte App fehlgeschlagen": Stellen Sie sicher, dass die App nicht zwangsweise gestoppt wurde. .

Und das war die Antwort des Firebase-Teams ->

Dies ist ein bekanntes Problem, das durch eine von einigen OEMs implementierte Batterieoptimierung verursacht wird. Wenn eine App im App-Umschalter weggewischt wird, wird die Anwendung so behandelt, als wäre sie zwangsweise gestoppt worden. Dies ist nicht das Standardverhalten von Android. Der unglückliche Nebeneffekt davon ist, dass der FCM-Dienst für Ihre App nicht mehr ausgeführt werden kann. Wir arbeiten daran, dieses Verhalten von unserer Seite aus zu verbessern, aber die eigentliche Lösung muss von der OEM-Seite kommen.

Hier steht OEM für Original Equipment Manufacturer .

Stellen Sie für alle, die nach dem Ausprobieren der oben genannten Lösungen damit zu kämpfen haben, sicher, dass die beim Erstellen des Benachrichtigungskanals verwendete Kanal-ID mit der im Benachrichtigungs-Builder festgelegten Kanal-ID identisch ist .

const val CHANNEL_ID = "EXAMPLE_CHANNEL_ID"

// create notification channel
val notificationChannel = NotificationChannel(CHANNEL_ID, 
NOTIFICATION_NAME, NotificationManager.IMPORTANCE_HIGH)

// building notification
NotificationCompat.Builder(context)
                    .setSmallIcon(android.R.drawable.ic_input_add)
                    .setContentTitle("Title")
                    .setContentText("Subtitle")   
                    .setPriority(NotificationCompat.PRIORITY_MAX)
                    .setChannelId(CHANNEL_ID)

private void addNotification() {
                NotificationCompat.Builder builder =
                new NotificationCompat.Builder(this)
                .setSmallIcon(R.drawable.ic_launcher_background)
                .setContentTitle("Notifications Example")
                .setContentText("This is a test notification");
                Intent notificationIntent = new Intent(this, MainActivity.class);
                PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent,
                PendingIntent.FLAG_UPDATE_CURRENT);
                builder.setContentIntent(contentIntent);
                // Add as notification
                NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
                if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O)
                {
                NotificationChannel nChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "NOTIFICATION_CHANNEL_NAME", NotificationManager.IMPORTANCE_HIGH);
                nChannel.enableLights(true);
                assert manager != null;
                builder.setChannelId(NOTIFICATION_CHANNEL_ID);
                manager.createNotificationChannel(nChannel);
                }
                assert manager != null;
                manager.notify(0, builder.build());
    }

Die folgende Methode zeigt die Benachrichtigung an , wobei großer Text und Einfrieren aktiviert sind (die Benachrichtigung wird auch nach dem Wischen durch den Benutzer nicht entfernt). Wir benötigen den NotificationManager-Service

public static void showNotificationOngoing(Context context,String title) {
        NotificationManager notificationManager =
                (NotificationManager) context.getSystemService(NOTIFICATION_SERVICE);

        PendingIntent contentIntent = PendingIntent.getActivity(context, 0,
                new Intent(context, MainActivity.class), PendingIntent.FLAG_UPDATE_CURRENT);

        Notification.Builder notificationBuilder = new Notification.Builder(context)
                .setContentTitle(title + DateFormat.getDateTimeInstance().format(new Date()) + ":" + accuracy)
                .setContentText(addressFragments.toString())
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentIntent(contentIntent)
                .setOngoing(true)
                .setStyle(new Notification.BigTextStyle().bigText(addressFragments.toString()))
                .setAutoCancel(true);
        notificationManager.notify(3, notificationBuilder.build());
}

Methode zum Entfernen von Benachrichtigungen

public static void removeNotification(Context context){
    NotificationManager notificationManager =
            (NotificationManager) context.getSystemService(NOTIFICATION_SERVICE);
    notificationManager.cancelAll();
}

Quelle Link -

NotificationCompat.Builder(Context context)

bereits veraltet für Version größer oder gleich Android Oreo. Sie können die Implementierung in using ändern

NotificationCompat.Builder(Context context, String channelId)

fun pushNotification(message: String?, clickAtion: String?) {
        val ii = Intent(clickAtion)
        ii.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
        val pendingIntent = PendingIntent.getActivity(this, REQUEST_CODE, ii, PendingIntent.FLAG_ONE_SHOT)

        val soundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION)

        val largIcon = BitmapFactory.decodeResource(applicationContext.resources,
                R.mipmap.ic_launcher)


        val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager

        val channelId = "default_channel_id"
        val channelDescription = "Default Channel"
// Since android Oreo notification channel is needed.
//Check if notification channel exists and if not create one
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            var notificationChannel = notificationManager.getNotificationChannel(channelId)
            if (notificationChannel != null) {
                val importance = NotificationManager.IMPORTANCE_HIGH //Set the importance level
                notificationChannel = NotificationChannel(channelId, channelDescription, importance)
               // notificationChannel.lightColor = Color.GREEN //Set if it is necesssary
                notificationChannel.enableVibration(true) //Set if it is necesssary
                notificationManager.createNotificationChannel(notificationChannel)


                val noti_builder = NotificationCompat.Builder(this)
                        .setContentTitle("MMH")
                        .setContentText(message)
                        .setSmallIcon(R.drawable.ic_launcher_background)
                        .setChannelId(channelId)
                        .build()
                val random = Random()
                val id = random.nextInt()
                notificationManager.notify(id,noti_builder)

            }

        }
        else
        {
            val notificationBuilder = NotificationCompat.Builder(this)
                    .setSmallIcon(R.mipmap.ic_launcher).setColor(resources.getColor(R.color.colorPrimary))
                    .setVibrate(longArrayOf(200, 200, 0, 0, 0))
                    .setContentTitle(getString(R.string.app_name))

                    .setLargeIcon(largIcon)
                    .setContentText(message)
                    .setAutoCancel(true)
                    .setStyle(NotificationCompat.BigTextStyle().bigText(message))
                    .setSound(soundUri)
                    .setContentIntent(pendingIntent)


            val random = Random()
            val id = random.nextInt()
            notificationManager.notify(id, notificationBuilder.build())

        }



    }

Der folgende Code funktioniert für mich im Oreo, Sie können dies versuchen. hoffe es wird für dich funktionieren

private void sendNotification (Kontext ctx, String-Titel, int-Benachrichtigungsnummer, String-Nachricht, String-Subtext, Intent-Absicht) {
try {

            PendingIntent pendingIntent = PendingIntent.getActivity(ctx, notificationNumber, intent,
                    PendingIntent.FLAG_UPDATE_CURRENT);
            Uri url = null;           
            NotificationCompat.Builder notificationBuilder = null;
            try {
                if (Build.VERSION.SDK_INT >= 26) {

                    try{
                        NotificationManager notificationManager = (NotificationManager)getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);
                        notificationManager.deleteNotificationChannel(CHANNEL_ID_1);
                        notificationManager.deleteNotificationChannel(CHANNEL_ID_2);

                        if(!intent.getStringExtra("type").equalsIgnoreCase(""+TYPE_REQUEST)){
                            NotificationChannel breaking = new NotificationChannel(CHANNEL_ID_1, CHANNEL_ID_1_NAME, NotificationManager.IMPORTANCE_HIGH);
                            breaking.setShowBadge(false);
                            breaking.enableLights(true);
                            breaking.enableVibration(true);
                            breaking.setLightColor(Color.WHITE);
                            breaking.setVibrationPattern(new long[]{100, 200, 100, 200, 100, 200, 100});
                            breaking.setSound(url,new AudioAttributes.Builder().build());

                            notificationBuilder = new NotificationCompat.Builder(this,CHANNEL_ID_1)
                                    .setSmallIcon(R.mipmap.ic_launcher);
                            notificationManager.createNotificationChannel(breaking);

                        }else{

                            NotificationChannel politics = new NotificationChannel(CHANNEL_ID_2,CHANNEL_ID_2_NAME, NotificationManager.IMPORTANCE_DEFAULT);
                            politics.setShowBadge(false);
                            politics.enableLights(true);
                            politics.enableVibration(true);
                            politics.setLightColor(Color.BLUE);
                            politics.setVibrationPattern(new long[]{100, 200, 100, 200, 100});
                            politics.setSound(url,new AudioAttributes.Builder().build());

                            notificationBuilder = new NotificationCompat.Builder(this,CHANNEL_ID_2)
                                    .setSmallIcon(R.mipmap.ic_launcher);
                            notificationManager.createNotificationChannel(politics);
                        }
                    }catch (Exception e){
                        e.printStackTrace();
                    }

                } else {
                    notificationBuilder = new NotificationCompat.Builder(ctx)
                            .setSmallIcon(R.mipmap.ic_launcher);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }

            if (notificationBuilder == null) {
                notificationBuilder = new NotificationCompat.Builder(ctx)
                        .setSmallIcon(R.mipmap.ic_launcher);
            }


            notificationBuilder.setContentTitle(title);          
            notificationBuilder.setSubText(subtext);
            notificationBuilder.setAutoCancel(true);

            notificationBuilder.setContentIntent(pendingIntent);
            notificationBuilder.setNumber(notificationNumber);
            NotificationManager notificationManager =
                    (NotificationManager) ctx.getSystemService(Context.NOTIFICATION_SERVICE);

            notificationManager.notify(notificationNumber, notificationBuilder.build());

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

    }

In Android Oreo wird die Benachrichtigungs-App mithilfe von Kanälen und der NotificationHelper-Klasse ausgeführt. Sie sollte eine Kanal-ID und einen Kanalnamen haben.

Zuerst müssen Sie eine NotificationHelper-Klasse erstellen

public class NotificationHelper extends ContextWrapper {

private static final String EDMT_CHANNEL_ID="com.example.safna.notifier1.EDMTDEV";
private static final String EDMT_CHANNEL_NAME="EDMTDEV Channel";
private NotificationManager manager;

public  NotificationHelper(Context base)
{
    super(base);
    createChannels();
}
private void createChannels()
{
    NotificationChannel edmtChannel=new NotificationChannel(EDMT_CHANNEL_ID,EDMT_CHANNEL_NAME,NotificationManager.IMPORTANCE_DEFAULT);
    edmtChannel.enableLights(true);
    edmtChannel.enableVibration(true);
    edmtChannel.setLightColor(Color.GREEN);
    edmtChannel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);

    getManager().createNotificationChannel(edmtChannel);

}
public NotificationManager getManager()
{
   if (manager==null)
       manager=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
   return manager;

}
public NotificationCompat.Builder getEDMTChannelNotification(String title,String body)
{
    return new NotificationCompat.Builder(getApplicationContext(),EDMT_CHANNEL_ID)
            .setContentText(body)
            .setContentTitle(title)
            .setSmallIcon(R.mipmap.ic_launcher_round)
            .setAutoCancel(true);
    }
}

Erstellen Sie eine Schaltfläche in der Aktivitäts-XML-Datei und dann In der Hauptaktivität

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    helper=new NotificationHelper(this);

    btnSend=(Button)findViewById(R.id.btnSend);

    btnSend.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String title="Title";
            String content="Content";
            Notification.Builder builder=helper.getEDMTChannelNotification(title,content);
            helper.getManager().notify(new Random().nextInt(),builder.build());
        }
    });

}

Führen Sie dann Ihr Projekt aus

Sie müssen einen Benachrichtigungskanal für API-Level über 26 (oreo) erstellen.

`NotificationChannel channel = new NotificationChannel(STRING_ID,CHANNEL_NAME,NotificationManager.IMPORTANCE_HIGH);

STRING_ID = String-Benachrichtigungskanal-ID ist dieselbe wie in Notification.Builder wie folgt

`Notification notification = new Notification.Builder(this,STRING_ID)
            .setSmallIcon(android.R.drawable.ic_menu_help)
            .setContentTitle("Hello Notification")
            .setContentText("It is Working")
            .setContentIntent(pendingIntent)
            .build();`

Die Kanal-ID in der Benachrichtigung und in der Benachrichtigung sollte gleich sein. Der gesamte Code ist wie folgt. `

@RequiresApi(api = Build.VERSION_CODES.O)
  private void callNotification2() {

    Intent intent = new Intent(getApplicationContext(),MainActivity.class);
    PendingIntent pendingIntent = PendingIntent.getActivity(this,11, 
    intent,PendingIntent.FLAG_UPDATE_CURRENT);
    Notification notification = new Notification.Builder(this,"22")
            .setSmallIcon(android.R.drawable.ic_menu_help)
            .setContentTitle("Hello Notification")
            .setContentText("It is Working")
            .setContentIntent(pendingIntent)
            .build();
    NotificationChannel channel = new 
    NotificationChannel("22","newName",NotificationManager.IMPORTANCE_HIGH);
    NotificationManager manager = (NotificationManager) 
    getSystemService(NOTIFICATION_SERVICE);
    manager.createNotificationChannel(channel);
    manager.notify(11,notification);

    }'

    NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, "CHANNEL_ID")
            ........

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

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        CharSequence name = "Hello";// The user-visible name of the channel.
        int importance = NotificationManager.IMPORTANCE_HIGH;
        NotificationChannel mChannel = new NotificationChannel(CHANNEL_ID, name, importance);
        mNotificationManager.createNotificationChannel(mChannel);
    }
    mNotificationManager.notify(notificationId, notificationBuilder.build());