Android 传感器

1. 光照传感器

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/light_level"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
         />

</RelativeLayout>

MainActivity.java

package liqing.lightsensortest;

import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private SensorManager sensorManager;
    private TextView lightLevel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        lightLevel = (TextView) findViewById(R.id.light_level);

        //获取系统传感器的管理器
        sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        //得到 光照传感器
        Sensor sensor = sensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
        // 光照传感器注册(register)监听,参数为(SensorEventListener实例,传感器对象,输出信息速率)
        sensorManager.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_NORMAL);
    }

    private SensorEventListener listener = new SensorEventListener() {
        @Override
        public void onSensorChanged(SensorEvent event) {
            float value = event.values[0];
            lightLevel.setText("Current light level is " + value + " lx ");

        }

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

        }
    };

    @Override
    protected void onDestroy() {

        super.onDestroy();
        if (sensorManager != null) {
            //注销监听
            sensorManager.unregisterListener(listener);
        }
    }

}

2. 加速器传感器(摇一摇)

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/light_level"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        />

</RelativeLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {
    private SensorManager sensorManager;
    private TextView lightLevel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        lightLevel = (TextView) findViewById(R.id.light_level);


        sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        //得到 accelerometer(加速器)传感器
        Sensor sensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);

        sensorManager.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_NORMAL);
    }

    private SensorEventListener listener = new SensorEventListener() {
        @Override
        public void onSensorChanged(SensorEvent event) {
            //方向传感器SensorEvent的取值有X轴,Y轴,Z轴,去绝对值Math.abs()
            float x = Math.abs(event.values[0]);
            float y = Math.abs(event.values[1]);
            float z = Math.abs(event.values[2]);
            if (x > 15 || y > 15 || z > 15) {
                lightLevel.setText("摇一摇 ");
            }


        }

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

        }
    };

    @Override
    protected void onDestroy() {

        super.onDestroy();
        if (sensorManager != null) {
            //注销监听
            sensorManager.unregisterListener(listener);
        }
    }

}

3.方向传感器(赛车游戏控制方向) 使用加速传感器和地磁传感器,通过getRotationMatrix()和getOrientation()得到XYZ旋转值

main_activity.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/light_level"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
         />

</RelativeLayout>

MainActivity.java

package liqing.lightsensortest;

import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private SensorManager sensorManager;
    private TextView textView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = (TextView) findViewById(R.id.light_level);
        sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        //得到 accelerometer(加速器)传感器
        Sensor accelerometerSensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        //带到 magnetic_FIELD(地磁的_领域)传感器
        Sensor magneticSensor = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
        //注意(SENSOR_DELAY_GAME)传感器的速率改变的相当快
        sensorManager.registerListener(listener, accelerometerSensor, SensorManager.SENSOR_DELAY_GAME);
        sensorManager.registerListener(listener, magneticSensor, SensorManager.SENSOR_DELAY_GAME);

    }

    private SensorEventListener listener = new SensorEventListener() {
        float[] accelerometerValues = new float[3];
        float[] magneticValues = new float[3];

        @Override
        public void onSensorChanged(SensorEvent event) {
            //注意SensorEvent是所以传感器的信息(包括类型和值)
            switch (event.sensor.getType()) {
                case Sensor.TYPE_ACCELEROMETER:
                    //clone()克隆
                    accelerometerValues = event.values.clone();
                    break;
                case Sensor.TYPE_MAGNETIC_FIELD:
                    //clone()克隆
                    magneticValues = event.values.clone();
                    break;
                default:
                    break;
            }
            float[] R = new float[9];//矩阵的值
            float[] values = new float[3];//X,Y,Z旋转的值
            //getRotationMatrix(得到旋转矩阵)
            SensorManager.getRotationMatrix(R, null, accelerometerValues, magneticValues);
            //getOrientation(得到选中的值)
            SensorManager.getOrientation(R, values);
            textView.setText(
                    "X=" + values[0] + "\n" 
                    + "Y=" + values[1] + "\n" 
                    + "Z=" + values[2] + "\n");
        }
        @Override
        public void onAccuracyChanged(Sensor sensor, int accuracy) {

        }
    };

    @Override
    protected void onDestroy() {

        super.onDestroy();
        if (sensorManager != null) {
            //注销监听
            sensorManager.unregisterListener(listener);
        }
    }

}