Android重力感应示例 .

android中的很多游戏的游戏都使用了重力感应的技术，就研究了一下重力感应

以屏幕的左下方为原点，箭头指向的方向为正。从-10到10，以浮点数为等级单位，想象以下情形：

 

手机屏幕向上（z轴朝天）水平放置的时侯，（x，y，z）的值分别为（0，0，10）；

手机屏幕向下（z轴朝地）水平放置的时侯，（x，y，z）的值分别为（0，0，-10）；

手机屏幕向左侧放（x轴朝天）的时候，（x，y，z）的值分别为（10，0，0）；

手机竖直（y轴朝天）向上的时候，（x，y，z）的值分别为（0，10，0）；

其他的如此类推，规律就是：朝天的就是正数，朝地的就是负数。

利用x,y,z三个值求三角函数，就可以精确检测手机的运动状态了。

代码实例：

AndroidManifest.xml

<uses-permission android:name="android.hardware.sensor.accelerometer"/>

代码很简单，直接看源码，最后提供了源码下载

Java Code:

 

package com.learn.sunboy;

import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.MotionEvent;
import android.widget.Toast;

public class TestSensor extends Activity{

    private SensorManager mSensorManager = null;
    private Sensor mSensor = null;
    private float x, y, z;

    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);

        mSensorManager = (SensorManager)this.getSystemService(SENSOR_SERVICE);
        mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
    }


    SensorEventListener lsn = new SensorEventListener() {

        @Override
        public void onSensorChanged(SensorEvent event) {
            x = event.values[SensorManager.DATA_X];
            y = event.values[SensorManager.DATA_Y];
            z = event.values[SensorManager.DATA_Z];
        }

        @Override
        public void onAccuracyChanged(Sensor sensor, int accuracy) {
            // TODO Auto-generated method stub

        }
    };

    @Override
    public boolean onTouchEvent(MotionEvent event){

        if(event.getAction() == MotionEvent.ACTION_DOWN){

            mSensorManager.registerListener(lsn, mSensor, SensorManager.SENSOR_DELAY_GAME);

            String str = "x=" + x + "; y=" + y + "; z=" + z;
            Toast.makeText(getApplicationContext(), str, Toast.LENGTH_LONG).show();
        }

        return super.onTouchEvent(event);
    }

    @Override
    public void onResume(){
        mSensorManager.registerListener(lsn, mSensor, SensorManager.SENSOR_DELAY_GAME);

        super.onResume();
    }


    @Override
    public void onPause(){
        mSensorManager.unregisterListener(lsn);

        super.onPause();
    }

}

package com.learn.sunboy; import android.app.Activity; import android.hardware.Sensor; import android.hardware.SensorEvent; import android.hardware.SensorEventListener; import android.hardware.SensorManager; import android.os.Bundle; import android.view.MotionEvent; import android.widget.Toast; public class TestSensor extends Activity{ private SensorManager mSensorManager = null; private Sensor mSensor = null; private float x, y, z; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); mSensorManager = (SensorManager)this.getSystemService(SENSOR_SERVICE); mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); } SensorEventListener lsn = new SensorEventListener() { @Override public void onSensorChanged(SensorEvent event) { x = event.values[SensorManager.DATA_X]; y = event.values[SensorManager.DATA_Y]; z = event.values[SensorManager.DATA_Z]; } @Override public void onAccuracyChanged(Sensor sensor, int accuracy) { // TODO Auto-generated method stub } }; @Override public boolean onTouchEvent(MotionEvent event){ if(event.getAction() == MotionEvent.ACTION_DOWN){ mSensorManager.registerListener(lsn, mSensor, SensorManager.SENSOR_DELAY_GAME); String str = "x=" + x + "; y=" + y + "; z=" + z; Toast.makeText(getApplicationContext(), str, Toast.LENGTH_LONG).show(); } return super.onTouchEvent(event); } @Override public void onResume(){ mSensorManager.registerListener(lsn, mSensor, SensorManager.SENSOR_DELAY_GAME); super.onResume(); } @Override public void onPause(){ mSensorManager.unregisterListener(lsn); super.onPause(); } }
运行效果：

 

注明：这是在模拟器上截图（SDK  V1.5）, 由于模拟器无法感应重力，请大家在物理机上测试