我正在尝试为使用手机的accerlerometer的android构建一个计步器应用程序。不用重新启动手机,它可以提供几乎准确的读数。对于每个步骤,它会将该值增加1.当移动设备重新启动时,步骤计数器值将变为0,因此我使用sharedPreferences保存了以前的读数值。但是,当我启动移动设备并开始步行时,对于每个步骤,步长计数器都会递增2.如何解决?不寻常的计数器读数
public class Pedometer extends Activity implements SensorEventListener {
private TextView textView;
private SensorManager mSensorManager;
private Sensor mStepCounterSensor;
private Sensor mStepDetectorSensor;
SharedPreferences sharedPreferences;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pedometer);
textView = (TextView) findViewById(R.id.textview);
mSensorManager = (SensorManager)
getSystemService(Context.SENSOR_SERVICE);
mStepCounterSensor = mSensorManager
.getDefaultSensor(Sensor.TYPE_STEP_COUNTER);
mStepDetectorSensor = mSensorManager
.getDefaultSensor(Sensor.TYPE_STEP_DETECTOR);
}
@Override
public void onSensorChanged(SensorEvent event) {
sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = sharedPreferences.edit();
Sensor sensor = event.sensor;
float[] values = event.values;
int value = -1;
if (values.length > 0) {
value = (int) values[0];
}
int temp = sharedPreferences.getInt("steps", 0);
if (temp > value) {
temp = temp + 1;
editor.putInt("steps", temp).commit();
} else {
editor.putInt("steps", value).commit();
}
int count = sharedPreferences.getInt("steps", 0);
if (sensor.getType() == Sensor.TYPE_STEP_COUNTER) {
textView.setText("Step Counter Detected : " + count);
} else if (sensor.getType() == Sensor.TYPE_STEP_DETECTOR) {
// For test only. Only allowed value is 1.0 i.e. for step taken
textView.setText("Step Detector Detected : " + count);
}
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
@Override
protected void onResume() {
super.onResume();
mSensorManager.registerListener(this, mStepCounterSensor,
SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, mStepDetectorSensor,
SensorManager.SENSOR_DELAY_FASTEST);
}
@Override
protected void onStop() {
super.onStop();
mSensorManager.unregisterListener(this, mStepCounterSensor);
mSensorManager.unregisterListener(this, mStepDetectorSensor);
}
}
我建议不要在每个'onSensorChangedEvent'上初始化'SharedPreferences'和'Editor'。这是很多工作,并且您不必要地一次又一次地创建这些对象。在onCreate()初始化一次() – Opiatefuchs