传感器使用

通过获取系统服务得到SensorManager

注册一个监听器SensorEventListener，数据处理过程就在监听器里面

光线触感器

package com.itheima.sensor;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class MainActivity extends Activity {
	private SensorManager sm;
	private MyListener listener;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		//获取系统服务
		sm = (SensorManager) getSystemService(SENSOR_SERVICE);
		//光线传感器  参数指定获取什么类型的传感器，也可以指定获取所有传感器
		Sensor sensor = sm.getDefaultSensor(Sensor.TYPE_LIGHT);
		listener = new MyListener();
		//注册一个监听器
		//第三参数代表采样频率，频率越高，精度越高，越费电
		sm.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_UI);
	}

	private class MyListener implements SensorEventListener{
		@Override
		public void onSensorChanged(SensorEvent event) {
			//不同类型的传感器，values的意义是不一样的   这里指的是光线的强弱
			float light = event.values[0];
			System.out.println("light:"+light);
		}
		@Override
		public void onAccuracyChanged(Sensor sensor, int accuracy) {
			
		}
	}
	@Override
	protected void onDestroy() {
		//应用程序关掉之后传感器还会一直在工作，所以需要把监听器注销掉并且置为null
		sm.unregisterListener(listener);
		listener = null;
		super.onDestroy();
	}

}

方向传感器

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000000"
    tools:context=".MainActivity" >

    <ImageView
        android:id="@+id/iv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:src="@drawable/zn" />

</RelativeLayout>

package com.itheima.sensor;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.animation.Animation;
import android.view.animation.RotateAnimation;
import android.widget.ImageView;

public class MainActivity extends Activity {
	private SensorManager sm;
	private MyListener listener;
	private ImageView iv;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		sm = (SensorManager) getSystemService(SENSOR_SERVICE);
		iv = (ImageView) findViewById(R.id.iv);
		//方向传感器  虽然过时了，但是为了兼容低版本，还是用这个
		Sensor sensor = sm.getDefaultSensor(Sensor.TYPE_ORIENTATION);
		listener = new MyListener();
		//SENSOR_DELAY_GAME改成游戏模式的采集频率
		sm.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_GAME);
	}

	private class MyListener implements SensorEventListener{
		float lastangle = 0;
		@Override
		public void onSensorChanged(SensorEvent event) {
			// 0=North, 90=East, 180=South, 270=West  
			float angle = event.values[0];//手机与正北方向的夹角
			System.out.println("angle:"+angle);
			
			RotateAnimation ra = new RotateAnimation(-lastangle, angle,
					Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
			iv.startAnimation(ra);
			lastangle = angle;
		}
		@Override
		public void onAccuracyChanged(Sensor sensor, int accuracy) {
			
		}
	}
	@Override
	protected void onDestroy() {
		sm.unregisterListener(listener);
		listener = null;
		super.onDestroy();
	}

}