WorkManager是用于维护延迟或后台执行任务的库。在特定条件下，WorkManager可以在应用程序处于前台时显示通知。使用setForeground()方法来设置任务优先级，并允许在应用程序处于前台时显示通知。

以下是示例代码：

class MyWorker extends Worker {
    private static final String CHANNEL_ID = "MY_CHANNEL_ID";
    private static final int NOTIFICATION_ID = 1;

    public MyWorker(@NonNull Context context, @NonNull WorkerParameters params) {
        super(context, params);
    }

    @NonNull
    @Override
    public Result doWork() {
        // Do some work here
        // ...

        // Set the priority of the worker
        setForegroundAsync(createForegroundInfo());

        // ...

        return Result.success();
    }

    private ForegroundInfo createForegroundInfo() {
        // Create a notification channel for the notification
        NotificationManager notificationManager =
                (NotificationManager) getApplicationContext().
                        getSystemService(Context.NOTIFICATION_SERVICE);
        if (notificationManager != null &&
                Build.VERSION.SDK_INT >= Build.VERSION_CODES.O &&
                notificationManager.getNotificationChannel(CHANNEL_ID) == null) {
            CharSequence name = "My Channel";
            String description = "My Channel Description";
            int importance = NotificationManager.IMPORTANCE_HIGH;
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
            channel.setDescription(description);
            notificationManager.createNotificationChannel(channel);
        }

        // Create the notification
        Notification notification =
                new NotificationCompat.Builder(getApplicationContext(), CHANNEL_ID)
                        .setContentTitle("My Notification")
                        .setContentText("This is my notification.")
                        .setSmallIcon(R.drawable.ic_notification)
                        .build();

        // Return the foreground info
        return new ForegroundInfo(NOTIFICATION_ID, notification);
    }
}