在后台获取步进传感器数据并存储在 SharedPreference/SQLite

Question

我尝试了很多方法来在后台获取传感器数据并将值存储到共享首选项或 SQLite 中，但是 none 方法有效。我认为这是因为 Android 奥利奥背景限制的东西。

我试过了

带广播接收器的警报管理器
带服务的警报管理器

现在我正在使用 WorkManager。也没有真正工作。我究竟做错了什么？现在是不是后台获取不到传感器数据了？还有其他替代方法吗？

MainActivity.java

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    localDatabaseHelper = new LocalDatabaseHelper(getApplicationContext());
    sharedPreferences = getSharedPreferences("TEST STORAGE", MODE_PRIVATE);

    sensorManager = (SensorManager) getApplicationContext().getSystemService(Context.SENSOR_SERVICE);
    stepSensor = sensorManager.getDefaultSensor(Sensor.TYPE_STEP_COUNTER);

    WorkManager.getInstance(getApplicationContext()).cancelAllWorkByTag("Update-Shared-Preference");
    WorkRequest updateSharedPreference = new OneTimeWorkRequest.Builder(UpdateStepWork.class)
            .addTag("Update-Shared-Preference")
            .build();

    WorkManager.getInstance(getApplicationContext()).enqueue(updateSharedPreference);
}

Work

public class UpdateStepWork extends Worker implements SensorEventListener {

private SharedPreferences sharedPreferences;
private SensorManager sensorManager;
private Sensor stepSensor;
private LocalDatabaseHelper localDatabase;

public UpdateStepWork(@NonNull Context context, @NonNull WorkerParameters workerParams) {
    super(context, workerParams);
}

@NonNull
@Override
public Result doWork() {

    Log.i("WORK", "STARTED");
    sharedPreferences = getApplicationContext().getSharedPreferences("TEST STORAGE", Context.MODE_PRIVATE);
    sensorManager = (SensorManager) getApplicationContext().getSystemService(Context.SENSOR_SERVICE);
    stepSensor = sensorManager.getDefaultSensor(Sensor.TYPE_STEP_COUNTER);
    localDatabase = new LocalDatabaseHelper(getApplicationContext());

    WorkManager.getInstance(getApplicationContext()).cancelAllWorkByTag("Update-Shared-Preference");
    WorkRequest updateSharedPreference = new OneTimeWorkRequest.Builder(UpdateStepWork.class)
            .setInitialDelay(5, TimeUnit.SECONDS)
            .addTag("Update-Shared-Preference")
            .build();

    WorkManager.getInstance(getApplicationContext()).enqueue(updateSharedPreference);

    sensorManager.unregisterListener(this, stepSensor);
    if(sensorManager.registerListener(this, stepSensor, SensorManager.SENSOR_DELAY_NORMAL)){
        return Worker.Result.success();
    }else
        return Worker.Result.failure();
}



@Override
public void onSensorChanged(SensorEvent event) {
    int steps = (int) event.values[0];

    Log.i("Steps from sensor", steps + "");

    if(sharedPreferences.edit().putInt("steps", steps).commit()){
        Log.i("Shared Preference", "SUCCESS STORED: " + steps);

        if(localDatabase.updateDailyData(steps)){
            Log.i("LOCAL DATABASE", "SUCCESS AT " + getCurrentTimeStamp());
            Cursor data = localDatabase.getData();

            while (data.moveToNext()) {
                Log.i("DATA", data.getString(0) + "    " + data.getInt(1));
            }
        }

    }else{
        Log.i("Shared Preference", "FAILED STORED: " + steps);
    }
    sensorManager.unregisterListener(this, stepSensor);
    sensorManager = null;
}

Answer 1

在后台收集传感器数据的典型方法是使用 foreground service。

SharedPreferences 不是存储传感器数据的理想方式。我建议您将传感器数据存储在 .csv 文件或数据库中。

在后台获取步进传感器数据并存储在 SharedPreference/SQLite

Get Step Sensor Data in background and store in SharedPreference/SQLite

java

android

background

sensors