Android:从 Azimuth、roll & pitch 获取设备方向

Question

我需要获取更新的设备方向，但我必须将我的 Activity 固定为纵向(我在布局 xml 文件中所做的)，这阻止了我使用它:

int rotation = getWindowManager().getDefaultDisplay().getRotation();

因为它总是给我纵向旋转，

所以，我尝试依靠传感器。我发现 Sensor.TYPE_ORIENTATION 已被弃用，所以我使用了 Sensor.TYPE_ACCELEROMETER 和 Sensor.TYPE_MAGNETIC_FIELD 的组合，这是事件听众:

SensorEventListener sensorEventListener = new SensorEventListener() {
    float[] mGravity;
    float[] mGeomagnetic;

    @Override
    public void onSensorChanged(SensorEvent event) {
        if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER)
            mGravity = event.values;
        if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD)
            mGeomagnetic = event.values;
        if (mGravity != null && mGeomagnetic != null) {
            float R[] = new float[9];
            float I[] = new float[9];
            boolean success = SensorManager.getRotationMatrix(R, I, mGravity, mGeomagnetic);
            if (success) {
                float orientationData[] = new float[3];
                SensorManager.getOrientation(R, orientationData);
                azimuth = orientationData[0];
                pitch = orientationData[1];
                roll = orientationData[2];
                // now how to use previous 3 values to calculate orientation
            }
        }
    }

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

    }
};

现在问题是，如何使用3个值azimuth, pitch & roll来检测当前设备方向作为其中之一:

• 横向(旋转 0)
• 纵向(旋转 90)
• 反向横向(旋转 180)
• 反向纵向(旋转 270)

Answer 1

我已经找到了，这里是计算函数，在读取 pitch & roll 后将在监听器中调用:

public static final int ORIENTATION_PORTRAIT = 0;
public static final int ORIENTATION_LANDSCAPE_REVERSE = 1;
public static final int ORIENTATION_LANDSCAPE = 2;
public static final int ORIENTATION_PORTRAIT_REVERSE = 3;
public int orientation = ORIENTATION_PORTRAIT;

private int calculateOrientation(int roll, int pitch) {
    if (((orientation == ORIENTATION_PORTRAIT || orientation == ORIENTATION_PORTRAIT_REVERSE)
            && (roll > -30 && roll < 30))) {
        if (averagePitch > 0)
            return ORIENTATION_PORTRAIT_REVERSE;
        else
            return ORIENTATION_PORTRAIT;
    } else {
        // divides between all orientations
        if (Math.abs(pitch) >= 30) {
            if (pitch > 0)
                return ORIENTATION_PORTRAIT_REVERSE;
            else
                return ORIENTATION_PORTRAIT;
        } else {
            if (averageRoll > 0) {
                return ORIENTATION_LANDSCAPE_REVERSE;
            } else {
                return ORIENTATION_LANDSCAPE;
            }
        }
    }
}

-- 更新--

& 这是我的完整 utility class实现

-- 更新--

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