android: proximity sensor issue

Question

Simple question, the I followed several tutorials but my proximity sensor doesn't work. I can only programmatically get the fact that it does exist, but the text doesn't change when I put my hand over the proximity sensor:

public class MainActivity extends Activity implements SensorEventListener {
private SensorManager sensorManager;
private Sensor sensor;
private TextView  textView;

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

    sensorManager =  (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    sensor = sensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);
    textView = (TextView) findViewById(R.id.textview);

    if(sensor == null) {
        textView.setText("No Proximity Sensor found");
    }else{
        textView.setText(sensor.getName() + " Found");
    }
}

@Override
protected void onResume() {
    super.onResume();
}

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

@Override
public void onSensorChanged(SensorEvent event) {
    if(event.sensor.getType() == Sensor.TYPE_PROXIMITY) {
        if(event.values[0] == 0) {
            textView.setText("You are near: " + String.valueOf(event.values[0]));
        }else{
            textView.setText("You are far: " + String.valueOf(event.values[0]));
        }
    }
}

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

}

}

Solution:

public class MainActivity extends Activity implements SensorEventListener {
private SensorManager sensorManager;
private Sensor sensor;
private TextView  textView;

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

    sensorManager =  (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    sensor = sensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);
    textView = (TextView) findViewById(R.id.textview);

    if(sensor == null) {
        textView.setText("No Proximity Sensor found");
    }else{
        textView.setText(sensor.getName() + " Found");
    }
    sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY), SensorManager.SENSOR_DELAY_NORMAL);
}

@Override
protected void onResume() {
    super.onResume();
    sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY), SensorManager.SENSOR_DELAY_NORMAL);
}

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

@Override
public void onSensorChanged(SensorEvent event) {
    if(event.sensor.getType() == Sensor.TYPE_PROXIMITY) {
        if(event.values[0] == 0) {
            textView.setText("You are near: " + String.valueOf(event.values[0]));
        }else{
            textView.setText("You are far: " + String.valueOf(event.values[0]));
        }
    }
}

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

}

Here's how I finally got it working, thanks for all the help guys :)

Answer 1

You have forgotten to attach the listener to the sensor:

sensor.registerListener(this);

Or better would be:

sensorManager.registerListener(this, sensor, SensorManager.SENSOR_DELAY_FASTEST);