Using proximity sensor in android

问题

I want to use proximity sensor in my project. I searched for proximity sensor tutorial. And I found a sensor tutorial at http://www.vogella.com/articles/AndroidSensor/article.html#sensoroverview_manager. I tried to use proximity sensor as following code:

@Override
public void onSensorChanged(SensorEvent event)
{
    if(event.sensor.getType() == Sensor.TYPE_PROXIMITY)
    {
        Toast.makeText(getApplicationContext(), "working", Toast.LENGTH_SHORT).show();
    }
}

My Activity is implementing SensorEventListener. But its not working. Do I need to use any permission to use proximity sensor? Or My code is wrong for doing this stuff. Your help will be very appreciated. Thank you

回答1:

I use this code:

import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements SensorEventListener {

    private SensorManager mSensorManager;
    private Sensor mProximity;
    private static final int SENSOR_SENSITIVITY = 4;

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


        mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        mProximity = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);

    }

    @Override
    protected void onResume() {
        super.onResume();
        mSensorManager.registerListener(this, mProximity, SensorManager.SENSOR_DELAY_NORMAL);
    }

    @Override
    protected void onPause() {
        super.onPause();
        mSensorManager.unregisterListener(this);
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        if (event.sensor.getType() == Sensor.TYPE_PROXIMITY) {
            if (event.values[0] >= -SENSOR_SENSITIVITY && event.values[0] <= SENSOR_SENSITIVITY) {
                //near
                Toast.makeText(getApplicationContext(), "near", Toast.LENGTH_SHORT).show();
            } else {
                //far
                Toast.makeText(getApplicationContext(), "far", Toast.LENGTH_SHORT).show();
            }
        }
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }

}

Also you can check this code in GitHub

回答2:

you are to register your listener. In your activity:

@Override
public final void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // Get an instance of the sensor service, and use that to get an instance of
    // a particular sensor.
    mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    mProximity = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);
}

@Override
protected void onResume() {
    // Register a listener for the sensor.
    super.onResume();
    mSensorManager.registerListener(this, mProximity, SensorManager.SENSOR_DELAY_NORMAL);
}

and then in you overriden onSensorChanged() method you can do your stuff with sensor data.

Sorry if my answer is too late =)

回答3:

The right way to use proximity sensor is via PowerManager. Forget about light sensor and use Android abstraction and already written code!

public class ProximityViaPowerManager {

private Context context;
private WakeLock proximityWakeLock;

public ProximityViaPowerManager(Context context) {
    this.context = context;
}

public boolean enableProximityWakeLock() {
    if (proximityWakeLock != null) {
      return true;
    }
    PowerManager powerManager = 
 context.getApplicationContext().getSystemService(Context.POWER_SERVICE);
    proximityWakeLock = powerManager.newWakeLock(PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK, TAG);
    proximityWakeLock.acquire();
    return true;
  }

  public void disableProximityWakeLock() {
    if (proximityWakeLock != null) {
      proximityWakeLock.release();
      proximityWakeLock = null;
    }
  }
}

Ensure correct enable/disable capability in Android life cycle resume/pause and add the permission to manifest:

<uses-permission android:name="android.permission.WAKE_LOCK" />

回答4:

You can follow this code which has the basic framework using which we can program any sensor.

Change this line

linearAcceleration = senseManager.getDefaultSensor(Sensor.TYPE_LINEAR_ACCELERATION);

proximity = senseManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);

来源：https://stackoverflow.com/questions/17967806/using-proximity-sensor-in-android

标签

android

proximity