如何使一个周期性的背景工作（15分钟的周期性间隔）无限期运行在奥利奥和以后？

Question

使用AlarmManagerApi设置重复警报：

public static void setAlarm(final Context context) {
    final AlarmManager manager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
    if (manager != null) {
        manager.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, 0, ALARM_INTERVAL,
                getAlarmPendingIntent(context));
    }
}

其中getAlarmPendingIntent方法如下所示：

private static PendingIntent getAlarmPendingIntent(final Context context) {
        return PendingIntent.getBroadcast(context, REQUEST_CODE, new Intent(context, AlarmReceiver.class), PendingIntent.FLAG_UPDATE_CURRENT);
    }

设置一个BroadcastReciever来累加警报：它在前台启动一个服务来完成所需的后台工作

public class AlarmReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, final Intent intent) {
        if (context == null || intent == null) {
            return;
        }

        if (intent.getAction() == null) {
            Intent monitorIntent = new Intent(context, TaskService.class);
            monitorIntent.putExtra(YourService.BATTERY_UPDATE, true);
            ContextCompat.startForegroundService(context, monitorIntent);
        }
    }

}

public class TaskService extends Service {
    private static final String CHANNEL_ID = "channel_01";
    private static final int NOTIFICATION_ID = 12345678;

    @Override
    public void onCreate() {
        super.onCreate();
        createNotificationChannel()
    }

    public void createNotificationChannel(){
        // create notification channel for notifications
        NotificationManager mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            CharSequence name = getString(R.string.app_name);
            NotificationChannel mChannel =
                    new NotificationChannel(CHANNEL_ID, name, NotificationManager.IMPORTANCE_DEFAULT);
            if (mNotificationManager != null) {
                mNotificationManager.createNotificationChannel(mChannel);
            }
        }
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        startForeground(NOTIFICATION_ID, getNotification());    
        BatteryCheckAsync batteryCheckAsync = new BatteryCheckAsync();
        batteryCheckAsync.execute();
        return START_STICKY;
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }


    private Notification getNotification() {
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setContentText(text)
                .setContentTitle("fetching battery level")
                .setOngoing(true)
                .setPriority(Notification.PRIORITY_LOW)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setWhen(System.currentTimeMillis());

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            builder.setChannelId(CHANNEL_ID);
        }

        return builder.build();
    }


    private class BatteryCheckAsync extends AsyncTask<Void, Void, Void> {

        @Override
        protected Void doInBackground(Void... arg0) {
            IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
            Intent batteryStatus = YourService.this.registerReceiver(null, ifilter);
            int level = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
            int scale = batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
            Log.i("Battery Charge Level",String.valueOf((level / (float) scale)));
            return null;

        }

        protected void onPostExecute() {
            YourService.this.stopSelf();
        }
    }
}

BatteryCheckAsync任务从后台获取电池电量，并在日志中显示当前电池电量。

从https://developer.android.com/training/monitoring-device-state/doze-standby上的android文档中，我发现它记录了

标准的AlarmManager警报（包括setExact（）和setWindow（））被推迟到下一个维护窗口。

如果您需要设置在打瞌睡时触发的警报，请使用setAndAllowWhileIdle（）或setExactAndAllowWhileIdle（）。

public static void setAlarm(final Context context) {
        final AlarmManager manager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
        if (manager == null) {
            return;
        }

        int SDK_INT = Build.VERSION.SDK_INT;
        if (SDK_INT < Build.VERSION_CODES.KITKAT) {
            manager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, ALARM_INTERVAL, getAlarmPendingIntent(context));
        } else if (SDK_INT < Build.VERSION_CODES.M) {
            manager.setExact(AlarmManager.ELAPSED_REALTIME_WAKEUP, ALARM_INTERVAL, getAlarmPendingIntent(context));
        } else {
            manager.setExactAndAllowWhileIdle(AlarmManager.ELAPSED_REALTIME_WAKEUP, ALARM_INTERVAL, getAlarmPendingIntent(context));
        }
    }

在Android Oreo及以上版本中，有没有一个解决方案可以保证在不确定的时间内执行周期性的后台任务？我正在安装Android奥利奥或以上的OnePlus设备上测试它。

Answer 1

尝试改变

public class AlarmReceiver extends WakefulBroadcastReceiver {
    //logic
}

还要更改警报管理器的事件alarmmanager.set(alarmmanager.rtc_wakeup，...)

因此，您将从doze模式唤醒设备并执行您的工作。