为什么在 Android 9 上不显示通知

Question

在 Android 9.0 上不显示通知，在 8 及更低版本上运行良好。 我在使用旧代码时遇到了问题，我读到需要在新的 android 版本上通过 Channel，我从互联网上获得了此代码，但仍然无法在 Android 9.0 上运行。我不知道为什么。 任何帮助将不胜感激。

当我通过互联网阅读时，一切看起来都很好。但没有显示通知。

    private void showSmallNotification( int icon, String title, String message, String timeStamp, PendingIntent resultPendingIntent){
        String CHANNEL_ID = Constants.ChannelID;
        String CHANNEL_NAME = "Notification";

        NotificationManager notificationManager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);;
        NotificationCompat.Builder notification;
        NotificationCompat.InboxStyle inboxStyle = new NotificationCompat.InboxStyle();

        inboxStyle.addLine(message);

        if (Build.VERSION.SDK_INT >= 26) {
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, CHANNEL_NAME, NotificationManager.IMPORTANCE_HIGH);
            channel.enableVibration(true);
            channel.setLightColor(Color.BLUE);
            channel.enableLights(true);
            channel.setSound(Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE + "://" + getApplicationContext().getPackageName() + "/" + R.raw.notification),
                    new AudioAttributes.Builder()
                            .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
                            .setUsage(AudioAttributes.USAGE_NOTIFICATION)
                            .build());
            channel.canShowBadge();
            notificationManager.createNotificationChannel(channel);
            notification = new NotificationCompat.Builder(getApplicationContext(), CHANNEL_ID);
        } else {
            notification = new NotificationCompat.Builder(getApplicationContext(),CHANNEL_ID);
        }
        notification
                .setVibrate(new long[]{0, 100})
                .setPriority(Notification.PRIORITY_MAX)
                .setLights(Color.BLUE, 3000, 3000)
                .setAutoCancel(true)
                .setContentTitle(title)
                .setContentIntent(resultPendingIntent)
                .setWhen(getTimeMilliSec(timeStamp))
                .setSmallIcon(R.mipmap.ic_launcher)
                .setStyle(inboxStyle)
                .setLargeIcon(BitmapFactory.decodeResource(this.getResources(), icon))
                .setContentText(message)
                .build();

        notificationManager.notify(CHANNEL_ID, 1, notification.build());
    }

Answer 1

我认为问题在于您没有在notificationBuilder 上使用setChannelId()。 （我冒昧地将notification 重命名为notificationBuilder，因为它就是这样。）

我删除了其中一行代码中多余的分号。

还要注意canShowBadge()是一个返回值的类方法，但不设置任何通知设置。我将其替换为setShowBadge(true)。

请阅读我在代码片段中留下的 cmets 以获得更多信息。

private void showSmallNotification( int icon, String title, String message, String timeStamp, PendingIntent resultPendingIntent){
        String CHANNEL_ID = Constants.ChannelID;
        String CHANNEL_NAME = "Notification";

        // I removed one of the semi-colons in the next line of code
        NotificationManager notificationManager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);
        NotificationCompat.InboxStyle inboxStyle = new NotificationCompat.InboxStyle();

        inboxStyle.addLine(message);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            // I would suggest that you use IMPORTANCE_DEFAULT instead of IMPORTANCE_HIGH
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, CHANNEL_NAME, NotificationManager.IMPORTANCE_HIGH);
            channel.enableVibration(true);
            channel.setLightColor(Color.BLUE);
            channel.enableLights(true);
            channel.setSound(Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE + "://" + getApplicationContext().getPackageName() + "/" + R.raw.notification),
                    new AudioAttributes.Builder()
                            .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
                            .setUsage(AudioAttributes.USAGE_NOTIFICATION)
                            .build());
            //channel.canShowBadge();
            // Did you mean to set the property to enable Show Badge?
            channel.setShowBadge(true);
            notificationManager.createNotificationChannel(channel);
        }

        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(getApplicationContext(), CHANNEL_ID)
            .setVibrate(new long[]{0, 100})
            .setPriority(Notification.PRIORITY_MAX)
            .setLights(Color.BLUE, 3000, 3000)
            .setAutoCancel(true)
            .setContentTitle(title)
            .setContentIntent(resultPendingIntent)
            .setWhen(getTimeMilliSec(timeStamp))
            .setSmallIcon(R.mipmap.ic_launcher)
            .setStyle(inboxStyle)
            .setLargeIcon(BitmapFactory.decodeResource(this.getResources(), icon))
            .setContentText(message);
        // Removed .build() since you use it below...no need to build it twice

        // Don't forget to set the ChannelID!!
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            notificationBuilder.setChannelId(ID_SPECIAL_OFFER_NOTIFICATION);
        }

        notificationManager.notify(CHANNEL_ID, 1, notificationBuilder.build());
    }

Answer 2

是的，这已经回答了，但需要帮助

 @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        int returnFlag = 0;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            createNotificationChannel();
            Notification.Builder builder = new Notification.Builder(this, ANDROID_CHANNEL_ID)
                    .setContentTitle(getString(R.string.app_name))
                    .setContentText("Mytrux Running")
                    .setAutoCancel(true);
            Notification notification = builder.build();
            startForeground(NOTIFICATION_ID, notification);
            returnFlag = START_NOT_STICKY;
        } else {
            NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
                    .setContentTitle(getString(R.string.app_name))
                    .setContentText("Mytrux is Running...")
                    .setPriority(NotificationCompat.PRIORITY_DEFAULT)
                    .setAutoCancel(true);
            Notification notification = builder.build();
            startForeground(NOTIFICATION_ID, notification);
            returnFlag = START_STICKY;
        }
        mHandlerTask.run();
        return returnFlag;
    }

并添加此方法

private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel serviceChannel = new NotificationChannel(
                    ANDROID_CHANNEL_ID,
                    "Foreground Service Channel",
                    NotificationManager.IMPORTANCE_DEFAULT
            );

            NotificationManager manager = getSystemService(NotificationManager.class);
            manager.createNotificationChannel(serviceChannel);
        }
    }

不要忘记在清单中添加服务。