onSensorChanged在锁定屏幕3分钟后停止调用

Question

我正在尝试开发一个简单的应用程序，该应用程序将在txt或csv文件中记录用户的活动(加速度计值(。

我的应用程序由两个java类组成MainActivity和MyService。MainActivity包括两个按钮，用于启动和停止服务以及所需的权限。但是，onSensorChanged通常会在锁定手机(关闭屏幕(后的前3分钟内进行日志记录，然后停止日志记录。我一打开屏幕，日志就会重新开始工作。txt文件中记录的行为相同。我发现，如果我忽略电池优化，这个应用程序似乎运行得很好。然而，我需要手机也能在瞌睡模式下工作，以节省一些电池电量。其他人也有类似的问题吗？

这是我的前台服务：

public class MyService extends Service implements SensorEventListener {
public static final String CHANNEL_ID = "ForegroundServiceChannel";
private static final String TAG = "MyService";
private Messenger messageHandler;

private SensorManager mSensorManager;
private Sensor mAccelerometer;
private Context mContext;
private PowerManager.WakeLock wakeLock = null;
//private HandlerThread mSensorThread;
//private Handler mHandler;
@SuppressLint("MissingPermission")
@Override
public void onCreate() {
super.onCreate();
Log.v("shake service startup", "registering for shake");
mContext = getApplicationContext();
//mHandler = new Handler(mSensorThread.getLooper());
mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
mAccelerometer = mSensorManager
.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mSensorManager.registerListener(this, mAccelerometer,
SensorManager.SENSOR_DELAY_NORMAL);

PowerManager manager = (PowerManager) getSystemService(Context.POWER_SERVICE);
wakeLock = manager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "Wakelock :: TAG");
// Register our receiver for the ACTION_SCREEN_OFF action. This will make our receiver
// code be called whenever the phone enters standby mode.
//IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
//registerReceiver(mReceiver, filter);
}

/*
// BroadcastReceiver for handling ACTION_SCREEN_OFF.
public BroadcastReceiver mReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
// Check action just to be on the safe side.
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
Log.v("shake mediator screen off","trying re-registration");
// Unregisters the listener and registers it again.
mSensorManager.unregisterListener(MyService.this);
mSensorManager.registerListener(MyService.this, mAccelerometer,
SensorManager.SENSOR_DELAY_NORMAL, mHandler);
}
}
};
*/
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
String input = intent.getStringExtra("inputExtra");
createNotificationChannel();
Intent notificationIntent = new Intent(this, MainActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this,
0, notificationIntent, 0);
Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
.setContentTitle("Foreground Service")
.setContentText(input)
.setSmallIcon(R.drawable.ic_launcher)
.setContentIntent(pendingIntent)
.build();
startForeground(1, notification);
return START_STICKY;
//stopSelf();
//return START_NOT_STICKY;
}
private void createNotificationChannel() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
NotificationChannel serviceChannel = new NotificationChannel(
CHANNEL_ID,
"Foreground Service Channel",
NotificationManager.IMPORTANCE_DEFAULT
);
NotificationManager manager = getSystemService(NotificationManager.class);
manager.createNotificationChannel(serviceChannel);
}
}
@Override
public void onDestroy() {
super.onDestroy();
if(mSensorManager != null){
//noinspection MissingPermission
mSensorManager.unregisterListener(MyService.this);
}
//unregisterReceiver(mReceiver);
try{
wakeLock.release();//always release before acquiring for safety just in case
}
catch(Exception e){
//probably already released
Log.e(TAG, e.getMessage());
}
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}

@Override
public void onSensorChanged(SensorEvent event) {
Log.d(TAG, "onSensorChanged: " + event.timestamp + " " + event.values[0] + " " + event.values[1] + " " + event.values[2]);
recordAccelValues(String.valueOf(event.timestamp),  event.values[0] + " " + event.values[1] + " " + event.values[2]);
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
private void recordAccelValues(String time, String accel_values) {
String record = time + " " + accel_values  + "n";
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
if (Build.VERSION.SDK_INT >= 23) {
File sdcard = Environment.getExternalStorageDirectory();
File dir = new File(sdcard.getAbsolutePath() + "/text/");
if(!dir.exists()) {
dir.mkdir();
}
File file = new File(dir, "dailyRecordsAccel.dat");
FileOutputStream os = null;
try {
os = new FileOutputStream(file, true);
os.write(record.getBytes());
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

}

正如你在代码中看到的，我尝试了我发现的其他问题中的几个建议，比如wakelock和Intent.ACTION_SCREEN_OFF，但它们似乎不起作用。当Droid/Nexus One上的屏幕关闭时，即使有WakeLock ，加速计也会停止提供样本

Answer 1

保持服务活力的唯一方法是避免应用程序的电池优化。这有两种可能请注意在这两种情况下，您都会使设备保持活动状态，这意味着设备永远不会休眠(显然会进入休眠状态(。这就是设备睡眠的全部意义，以避免像您这样的后台服务的未决工作。

• 使用AndroidWakeLocks，例如以下

val wakeLock: PowerManager.WakeLock =
(getSystemService(Context.POWER_SERVICE) as PowerManager).run {
newWakeLock(PowerManager. FULL_WAKE_LOCK, "MyApp::MyWakelockTag").apply {
acquire()
}
}

• 更改设置以避免特定应用程序的电池优化。正如你在问题中提到的

Answer 2

这是正常行为。安卓删除所有进程以节省电力。如果您想做一项工作，请用户保持屏幕打开，否则您可以使用AlarmManager只调用服务(Intent，Reciver(做"小工作"并再次进入睡眠状态。