Android-用重力傳感器做橫豎屏切換

在播放視頻的時候，可能要做橫豎屏的切換，但是，用戶可以設置自己的手機關掉屏幕旋轉，這個時候就需要想其他的辦法了，比如：重力傳感器。

 

public class ScreenSwitchUtils {
	
	private static final String TAG = ScreenSwitchUtils.class.getSimpleName();
	
	private volatile static ScreenSwitchUtils mInstance;
	
	private Activity mActivity;
	
	// 是否是豎屏
	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, 切換成橫屏);
						mActivity.setRequestedOrientation(0);
						isPortrait = false;
					}
				} else if ((orientation > 315 && orientation < 360) || (orientation > 0 && orientation < 45)) {
					if (!isPortrait) {
						Log.e(test,切換成豎屏);
						mActivity.setRequestedOrientation(1);
						isPortrait = true;
					}
				}
				break;
			default:
				break;
			}

		};
	};
	
	/** 返回ScreenSwitchUtils單例 **/
    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.);
        // 注冊重力感應器,監聽屏幕旋轉
        sm = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
        sensor = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        listener = new OrientationSensorListener(mHandler);

        // 根據 旋轉之後/點擊全屏之後 兩者方向一致,激活sm.
        sm1 = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
        sensor1 = sm1.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        listener1 = new OrientationSensorListener1();
    }
    
    /** 開始監聽 */
    public void start(Activity activity) {
    	Log.d(TAG, start orientation listener.);
        mActivity = activity;
        sm.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_UI);
    }

    /** 停止監聽 */
    public void stop() {
    	Log.d(TAG, stop orientation listener.);
    	sm.unregisterListener(listener);
		sm1.unregisterListener(listener1);
    }
    
    /**
     * 手動橫豎屏切換方向
     */
    public void toggleScreen() {
		sm.unregisterListener(listener);
		sm1.registerListener(listener1, sensor1,SensorManager.SENSOR_DELAY_UI);
		if (isPortrait) {
			isPortrait = false;
			// 切換成橫屏
			mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
		} else {
			isPortrait = true;
			// 切換成豎屏
			mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
		}
	}
    
    public boolean isPortrait(){
    	return this.isPortrait;
    }
    
    /**
	 * 重力感應監聽者
	 */
	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) {
				// 屏幕旋轉時
				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) {
				// 屏幕旋轉時
				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) {// 檢測到當前實際是橫屏
				if (!isPortrait) {
					sm.registerListener(listener, sensor,SensorManager.SENSOR_DELAY_UI);
					sm1.unregisterListener(listener1);
				}
			} else if ((orientation > 315 && orientation < 360) || (orientation > 0 && orientation < 45)) {// 檢測到當前實際是豎屏
				if (isPortrait) {
					sm.registerListener(listener, sensor,SensorManager.SENSOR_DELAY_UI);
					sm1.unregisterListener(listener1);
				}
			}
		}
	}
}

轉載請標明出處：http://blog.csdn.net/goldenfish1919/article/details/47423131

使用的時候：

 

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()) {
			// 切換成豎屏
			LayoutParams params1 = new RelativeLayout.LayoutParams(screenWidth, DensityUtil.dip2px(this, 160));
			videoView.setLayoutParams(params1);
			Toast.makeText(getApplicationContext(), 豎屏, 0).show();
			Log.e(test, 豎屏);
		} else {
			// 切換成橫屏
			LayoutParams params1 = new RelativeLayout.LayoutParams(screenHeight, screenWidth);
			videoView.setLayoutParams(params1);
			Toast.makeText(getApplicationContext(), 橫屏, 0).show();
			Log.e(test, 橫屏);
		}
	}

	@Override
	public void onClick(View arg0) {
		switch (arg0.getId()) {
		case R.id.iv_stretch:
			instance.toggleScreen();
			break;
		}
	}
}

調用了activity.setRequestedOrientation()以後，會觸發activity.onConfigurationChanged();可以在這裡面重新設置播放界面的大小。