如何检查光量?

How to check amount of light?

我用 Camera2API 工作,如果外面光线不足,我需要禁用拍照功能 ...

我考虑过,当用户使用标准相机时,他设置为闪光灯(自动模式)。

如果我没理解错的话,相机会使用某种传感器来检测光量,如果光量不够,闪光灯就会工作。

如何连接这个传感器?

您可以使用类似于此处列出的代码的内容:

https://developer.android.com/guide/topics/sensors/sensors_environment.html

像这样修改它以与光传感器一起工作:

public class SensorActivity extends Activity implements SensorEventListener {
  private SensorManager mSensorManager;
  private Sensor mLight;

  @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);
    mLight= mSensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
  }

  @Override
  public final void onAccuracyChanged(Sensor sensor, int accuracy) {
    // Do something here if sensor accuracy changes.
  }

  @Override
  public final void onSensorChanged(SensorEvent event) {
    float luminosity = event.values[0];
    // Do something with this sensor data.
  }

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

  @Override
  protected void onPause() {
    // Be sure to unregister the sensor when the activity pauses.
    super.onPause();
    mSensorManager.unregisterListener(this);
  }
}