详解Android开发中的重力传感器用法实例

private SensorManager sensorManager;private MySensorEventListener mySensorEventListener;mySensorEventListener= new MySensorEventListener();//这个监听器当然是我们自己定义的，在重力感应器感应到手机位置有变化的时候，我们可以采取相应的操作，这里紧紧是将x,y,z的值打印出来private final class MySensorEventListener implements SensorEventListener{@Override//可以得到传感器实时测量出来的变化值public void onSensorChanged(SensorEvent event) {//重力传感器if(event.sensor.getType()==Sensor.TYPE_ACCELEROMETER){float x = event.values[SensorManager.DATA_X];float y = event.values[SensorManager.DATA_Y];float z = event.values[SensorManager.DATA_Z];//tv_accelerometer是界面上的一个TextView标签，不再赘述tv_orientation.setText("Orientation:"+x+","+y+","+z);}}

protected void onResume() { Sensor sensor_accelerometer=sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); sensorManager.registerListener(mySensorEventListener,sensor_accelerometer, SensorManager.SENSOR_DELAY_UI);super.onResume();}

protected void onPause() {//注销所有传感器的监听sensorManager.unregisterListener(mySensorEventListener);super.onPause();}

public class ScreenSwitchUtils { private static final String TAG = ScreenSwitchUtils.class.getSimpleName(); private volatile static ScreenSwitchUtils mInstance; private Activity mActivity; // 是否是竖屏 private boolean isPortrait = true; private SensorManager sm; private OrientationSensorListener listener; private Sensor sensor; private SensorManager sm1; private Sensor sensor1; private OrientationSensorListener1 listener1; private Handler mHandler = new Handler() {  public void handleMessage(Message msg) {   switch (msg.what) {   case 888:    int orientation = msg.arg1;    if (orientation > 45 && orientation < 135) {    } else if (orientation > 135 && orientation < 225) {    } else if (orientation > 225 && orientation < 315) {     if (isPortrait) {      Log.e(test, 切换成横屏);      mActivity.setRequestedOrientation(0);      isPortrait = false;     }    } else if ((orientation > 315 && orientation < 360) || (orientation > 0 && orientation < 45)) {     if (!isPortrait) {      Log.e(test,切换成竖屏);      mActivity.setRequestedOrientation(1);      isPortrait = true;     }    }    break;   default:    break;   }  }; }; /** 返回ScreenSwitchUtils单例 **/ public static ScreenSwitchUtils init(Context context) {  if (mInstance == null) {   synchronized (ScreenSwitchUtils.class) {    if (mInstance == null) {     mInstance = new ScreenSwitchUtils(context);    }   }  }  return mInstance; } private ScreenSwitchUtils(Context context) {  Log.d(TAG, init orientation listener.);  // 注册重力感应器,监听屏幕旋转  sm = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);  sensor = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);  listener = new OrientationSensorListener(mHandler);  // 根据 旋转之后/点击全屏之后 两者方向一致,激活sm.  sm1 = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);  sensor1 = sm1.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);  listener1 = new OrientationSensorListener1(); } /** 开始监听 */ public void start(Activity activity) {  Log.d(TAG, start orientation listener.);  mActivity = activity;  sm.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_UI); } /** 停止监听 */ public void stop() {  Log.d(TAG, stop orientation listener.);  sm.unregisterListener(listener);  sm1.unregisterListener(listener1); } /**  * 手动横竖屏切换方向  */ public void toggleScreen() {  sm.unregisterListener(listener);  sm1.registerListener(listener1, sensor1,SensorManager.SENSOR_DELAY_UI);  if (isPortrait) {   isPortrait = false;   // 切换成横屏   mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);  } else {   isPortrait = true;   // 切换成竖屏   mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);  } } public boolean isPortrait(){  return this.isPortrait; } /**  * 重力感应监听者  */ public class OrientationSensorListener implements SensorEventListener {  private static final int _DATA_X = 0;  private static final int _DATA_Y = 1;  private static final int _DATA_Z = 2;  public static final int ORIENTATION_UNKNOWN = -1;  private Handler rotateHandler;  public OrientationSensorListener(Handler handler) {   rotateHandler = handler;  }  public void onAccuracyChanged(Sensor arg0, int arg1) {  }  public void onSensorChanged(SensorEvent event) {   float[] values = event.values;   int orientation = ORIENTATION_UNKNOWN;   float X = -values[_DATA_X];   float Y = -values[_DATA_Y];   float Z = -values[_DATA_Z];   float magnitude = X * X + Y * Y;   // Don't trust the angle if the magnitude is small compared to the y   // value   if (magnitude * 4 >= Z * Z) {    // 屏幕旋转时    float OneEightyOverPi = 57.29577957855f;    float angle = (float) Math.atan2(-Y, X) * OneEightyOverPi;    orientation = 90 - (int) Math.round(angle);    // normalize to 0 - 359 range    while (orientation >= 360) {     orientation -= 360;    }    while (orientation < 0) {     orientation += 360;    }   }   if (rotateHandler != null) {    rotateHandler.obtainMessage(888, orientation, 0).sendToTarget();   }  } } public class OrientationSensorListener1 implements SensorEventListener {  private static final int _DATA_X = 0;  private static final int _DATA_Y = 1;  private static final int _DATA_Z = 2;  public static final int ORIENTATION_UNKNOWN = -1;  public OrientationSensorListener1() {  }  public void onAccuracyChanged(Sensor arg0, int arg1) {  }  public void onSensorChanged(SensorEvent event) {   float[] values = event.values;   int orientation = ORIENTATION_UNKNOWN;   float X = -values[_DATA_X];   float Y = -values[_DATA_Y];   float Z = -values[_DATA_Z];   float magnitude = X * X + Y * Y;   // Don't trust the angle if the magnitude is small compared to the y   // value   if (magnitude * 4 >= Z * Z) {    // 屏幕旋转时    float OneEightyOverPi = 57.29577957855f;    float angle = (float) Math.atan2(-Y, X) * OneEightyOverPi;    orientation = 90 - (int) Math.round(angle);    // normalize to 0 - 359 range    while (orientation >= 360) {     orientation -= 360;    }    while (orientation < 0) {     orientation += 360;    }   }   if (orientation > 225 && orientation < 315) {// 检测到当前实际是横屏    if (!isPortrait) {     sm.registerListener(listener, sensor,SensorManager.SENSOR_DELAY_UI);     sm1.unregisterListener(listener1);    }   } else if ((orientation > 315 && orientation < 360) || (orientation > 0 && orientation < 45)) {// 检测到当前实际是竖屏    if (isPortrait) {     sm.registerListener(listener, sensor,SensorManager.SENSOR_DELAY_UI);     sm1.unregisterListener(listener1);    }   }  } }}

public class MainActivity extends Activity implements OnClickListener { private ScreenSwitchUtils instance; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  instance = ScreenSwitchUtils.init(this.getApplicationContext()); } @Override protected void onStart() {  super.onStart();  instance.start(this); } @Override protected void onStop() {  super.onStop();  instance.stop(); } @SuppressLint(NewApi) @Override public void onConfigurationChanged(Configuration newConfig) {  super.onConfigurationChanged(newConfig);  Log.e(test, onConfigurationChanged);  if (instance.isPortrait()) {   // 切换成竖屏   LayoutParams params1 = new RelativeLayout.LayoutParams(screenWidth, DensityUtil.dip2px(this, 160));   videoView.setLayoutParams(params1);   Toast.makeText(getApplicationContext(), 竖屏, 0).show();   Log.e(test, 竖屏);  } else {   // 切换成横屏   LayoutParams params1 = new RelativeLayout.LayoutParams(screenHeight, screenWidth);   videoView.setLayoutParams(params1);   Toast.makeText(getApplicationContext(), 横屏, 0).show();   Log.e(test, 横屏);  } } @Override public void onClick(View arg0) {  switch (arg0.getId()) {  case R.id.iv_stretch:   instance.toggleScreen();   break;  } }}