自动横屏切换

1.写一个工具类 ScreenSwitchUtils.java

import android.app.Activity;  import android.content.Context;  import android.content.pm.ActivityInfo;  import android.hardware.Sensor;  import android.hardware.SensorEvent;  import android.hardware.SensorEventListener;  import android.hardware.SensorManager;  import android.os.Handler;  import android.os.Message;    public class ScreenSwitchUtils {      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) {                      if (isPortrait) {                          //切换成横屏反向：ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE                          mActivity.setRequestedOrientation(8);                          isPortrait = false;                      }                  } else if (orientation > 135 && orientation < 225) {                      if (!isPortrait) {                          /*                          * 切换成竖屏反向：ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT(9),                          * ActivityInfo.SCREEN_ORIENTATION_SENSOR:根据重力感应自动旋转                          * 此处正常应该是上面第一个属性，但是在真机测试时显示为竖屏正向，所以用第二个替代                          */                          mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR);                          isPortrait = true;                      }                  } else if (orientation > 225 && orientation < 315) {                      if (isPortrait) {                          //切换成横屏：ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE                          mActivity.setRequestedOrientation(0);                          isPortrait = false;                      }                  } else if ((orientation > 315 && orientation < 360) || (orientation > 0 && orientation < 45)) {                      if (!isPortrait) {                          //切换成竖屏ActivityInfo.SCREEN_ORIENTATION_PORTRAIT                          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) {          // 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) {          mActivity = activity;          sm.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_UI);      }         /** 停止监听 */      public void stop() {          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);                  }              }          }      }  }  

2.在需要的Activity里引用

           private ScreenSwitchUtils instance;  

instance = ScreenSwitchUtils.init(this.getApplicationContext()); 

 //
    @Override  
    protected void onStart() {  
        super.onStart();  
        instance.start(this);  
    }  
   
    @Override  
    protected void onStop() {  
        super.onStop();  
        instance.stop();  
    }  
    //