Android 前台服务通知不显示

Question

我正在尝试启动前台服务。我收到服务确实启动的通知，但通知总是被抑制。我仔细检查了该应用程序是否允许在我设备上的应用程序信息中显示通知。这是我的代码：

 private void showNotification() {
    Intent notificationIntent = new Intent(this, MainActivity.class);
    notificationIntent.setAction(Constants.ACTION.MAIN_ACTION);
    notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
            | Intent.FLAG_ACTIVITY_CLEAR_TASK);
    PendingIntent pendingIntent = PendingIntent.getActivity(this, 0,
            notificationIntent, 0);

    Bitmap icon = BitmapFactory.decodeResource(getResources(),
            R.mipmap.ic_launcher);

    Notification notification = new NotificationCompat.Builder(getApplicationContext())
            .setContentTitle("Revel Is Running")
            .setTicker("Revel Is Running")
            .setContentText("Click to stop")
            .setSmallIcon(R.mipmap.ic_launcher)
            //.setLargeIcon(Bitmap.createScaledBitmap(icon, 128, 128, false))
            .setContentIntent(pendingIntent)
            .setOngoing(true).build();
    startForeground(Constants.FOREGROUND_SERVICE,
            notification);
    Log.e(TAG,"notification shown");

}

这是我在相关中看到的唯一错误： 06-20 12:26:43.635 895-930/? E/NotificationService: Suppressing notification from the package by user request.

原文由 Dreamers Org 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

问题是我使用的是 Android O，它需要更多信息。这是android O的成功代码。

     mNotifyManager = (NotificationManager) mActivity.getSystemService(Context.NOTIFICATION_SERVICE);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) createChannel(mNotifyManager);
    mBuilder = new NotificationCompat.Builder(mActivity, "YOUR_TEXT_HERE").setSmallIcon(android.R.drawable.stat_sys_download).setColor
            (ContextCompat.getColor(mActivity, R.color.colorNotification)).setContentTitle(YOUR_TITLE_HERE).setContentText(YOUR_DESCRIPTION_HERE);
    mNotifyManager.notify(mFile.getId().hashCode(), mBuilder.build());

@TargetApi(26)
private void createChannel(NotificationManager notificationManager) {
    String name = "FileDownload";
    String description = "Notifications for download status";
    int importance = NotificationManager.IMPORTANCE_DEFAULT;

    NotificationChannel mChannel = new NotificationChannel(name, name, importance);
    mChannel.setDescription(description);
    mChannel.enableLights(true);
    mChannel.setLightColor(Color.BLUE);
    notificationManager.createNotificationChannel(mChannel);
}

原文由 Dreamers Org 发布，翻译遵循 CC BY-SA 3.0 许可协议

Answer 2

这是因为 Android O bg 服务限制。

所以现在您需要调用 startForeground() 仅针对以 startForegroundService() 启动的服务，并在服务启动后的前 5 秒内调用它。

这是指南 - https://developer.android.com/about/versions/oreo/background#services

像这样：

 //Start service:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
  startForegroundService(new Intent(this, YourService.class));
} else {
  startService(new Intent(this, YourService.class));
}

然后创建并显示通知（如前所述使用频道）：

 private void createAndShowForegroundNotification(Service yourService, int notificationId) {

    final NotificationCompat.Builder builder = getNotificationBuilder(yourService,
         "com.example.your_app.notification.CHANNEL_ID_FOREGROUND", // Channel id
    NotificationManagerCompat.IMPORTANCE_LOW); //Low importance prevent visual appearance for this notification channel on top
    builder.setOngoing(true)
    .setSmallIcon(R.drawable.small_icon)
    .setContentTitle(yourService.getString(R.string.title))
    .setContentText(yourService.getString(R.string.content));

    Notification notification = builder.build();

    yourService.startForeground(notificationId, notification);

    if (notificationId != lastShownNotificationId) {
          // Cancel previous notification
          final NotificationManager nm = (NotificationManager) yourService.getSystemService(Activity.NOTIFICATION_SERVICE);
          nm.cancel(lastShownNotificationId);
    }
    lastShownNotificationId = notificationId;
}

public static NotificationCompat.Builder getNotificationBuilder(Context context, String channelId, int importance) {
    NotificationCompat.Builder builder;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        prepareChannel(context, channelId, importance);
        builder = new NotificationCompat.Builder(context, channelId);
    } else {
        builder = new NotificationCompat.Builder(context);
    }
    return builder;
}

@TargetApi(26)
private static void prepareChannel(Context context, String id, int importance) {
    final String appName = context.getString(R.string.app_name);
    String description = context.getString(R.string.notifications_channel_description);
    final NotificationManager nm = (NotificationManager) context.getSystemService(Activity.NOTIFICATION_SERVICE);

    if(nm != null) {
        NotificationChannel nChannel = nm.getNotificationChannel(id);

        if (nChannel == null) {
            nChannel = new NotificationChannel(id, appName, importance);
            nChannel.setDescription(description);
            nm.createNotificationChannel(nChannel);
        }
    }
}

请记住，即使您使用不同的频道 ID，您的前台通知也将具有与其他通知相同的状态，因此它可能与其他通知一起隐藏为一个组。使用不同的组来避免它。

原文由 v1k 发布，翻译遵循 CC BY-SA 4.0 许可协议