android：接近傳感器問題

Question

一個簡單的問題，我遵循了一些教程，但是我的接近傳感器不起作用。 我只能以編程方式得到它確實存在的事實，但是當我將手放在接近傳感器上時，文本不會更改：

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) {

}

}

解：

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) {

}

這是我終於可以正常工作的方式，感謝所有幫助人員:)

Answer 1

您忘記了將偵聽器連接到傳感器：

sensor.registerListener(this);

或更佳的是：

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