使用ContentObserver观察屏幕旋转

    //观察屏幕旋转设置变化，类似于注册动态广播监听变化机制
    private class RotationObserver extends ContentObserver {
        ContentResolver mResolver;

        public RotationObserver(Handler handler) {
            super(handler);
            mResolver = LinkMicActivity.this.getContentResolver();
        }

        //屏幕旋转设置改变时调用
        @Override
        public void onChange(boolean selfChange) {
            super.onChange(selfChange);
            //更新按钮状态
            if (isActivityCanRotation()) {
                onActivityRotation();
            } else {               
            }

        }

        public void startObserver() {
            mResolver.registerContentObserver(Settings.System.getUriFor(Settings.System.ACCELEROMETER_ROTATION), false, this);
        }

        public void stopObserver() {
            mResolver.unregisterContentObserver(this);
        }
    }

public void LinkMicActivity extends Activity {
      // 关注系统设置项“自动旋转”的状态切换
    private RotationObserver mRotationObserver = null; 
   @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mRotationObserver = new RotationObserver(new Handler());
        mRotationObserver.startObserver();
    }
        @Override
    public void onDestroy() {
        super.onDestroy();   
        mRotationObserver.stopObserver();
    }
}