我已经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，但它们都没有起作用。我认为这是因为Android Oreo的后台限制。
我尝试过：
- 使用广播接收器的闹钟管理器（Alarm Manager）
- 使用服务的闹钟管理器（Alarm Manager）
- 现在我正在使用WorkManager。但它也没有真正起作用。我做错了什么？现在在后台获取传感器数据是不可能的吗？还有其他替代的方法吗？
> 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;
    }