光照传感器---Sensor.TYPE_LIGHT

学习《Android第一行代码》笔记与实践！！！

1.布局
放置一个TextView，用于显示当前光照强度。

<TextView        android:id="@+id/tv_light_level"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="26sp"/>

2.activity

public class MainActivity extends AppCompatActivity {    @BindView(R.id.tv_light_level)    TextView tvLightLevel;    private SensorManager sensorManager;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ButterKnife.bind(this);        sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);        Sensor sensor = sensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);        sensorManager.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_NORMAL);    }    private SensorEventListener listener = new SensorEventListener() {        @Override        public void onSensorChanged(SensorEvent event) {            //values数组中第一个下标的值就是当前的光照强度            float value = event.values[0];            tvLightLevel.setText("当前光照强度：" + value + "lx");        }        @Override        public void onAccuracyChanged(Sensor sensor, int accuracy) {        }    };    @Override    protected void onDestroy() {        super.onDestroy();        if(sensorManager != null){            sensorManager.unregisterListener(listener);        }    }}