setRequestedOrientation(screenorientation);

但我希望获得方向更新,以便我可以对UI进行调整(想象一下HTC相机应用程序,只有按钮的图标改变方向).
所以我找到了this class.它提供了0到360之间的方向值.我可以过滤这个值,即完美区间[a,b],如果< x< b那么方向是横向还是纵向？计算意味着什么？任何提示？

OrientationEventListener myOrientationEventListener;
    int iOrientation;

    myOrientationEventListener = new OrientationEventListener(this,SensorManager.SENSOR_DELAY_norMAL)
    {

        @Override
        public void onorientationChanged(int iAngle)
        {                         // 0  15 30 45 60 75,90 105,120,135,150,165,180,195,210,225,240,255,270,285,300,315,330,345
            final int iLookup[] = {0,90,0}; // 15-degree increments 
            if (iAngle != ORIENTATION_UNKNowN)
            {
                int iNewOrientation = iLookup[iAngle / 15];
                if (iOrientation != iNewOrientation)
                {
                    iOrientation = iNewOrientation;
                    // take action on new orientation here
                }
            }
        }
    };

    // To display if orientation detection will work and enable it
    if (myOrientationEventListener.canDetectOrientation())
    {
    Toast.makeText(this,"Can DetectOrientation",Toast.LENGTH_LONG).show();
        myOrientationEventListener.enable();
    }
    else
    {
    Toast.makeText(this,"Can't DetectOrientation",Toast.LENGTH_LONG).show();
    }

我设法得到方位角,但是给出一个位置,我不知道如何继续计算我需要的角度.此外,我需要从北方和北极的转换.有人有这样的实现的例子吗？

提前致谢.

float azimuth = // get azimuth from the orientation sensor (it's quite simple)
Location currentLoc = // get location from GPS or network
// convert radians to degrees
azimuth = Math.todegrees(azimuth);
GeomagneticField geoField = new GeomagneticField(
             (float) currentLoc.getLatitude(),(float) currentLoc.getLongitude(),(float) currentLoc.getAltitude(),System.currentTimeMillis());
azimuth += geoField.getDeclination(); // converts magnetic north into true north
float bearing = currentLoc.bearingTo(target); // (it's already in degrees)
float direction = azimuth - bearing;

如果要绘制箭头或其他东西来指向方向,请使用canvas.rotate(–irection).我们传递一个负面的参数,因为画布旋转是逆时针的.

然而,我发现结果值取决于手机方向 – 旋转到右侧的景观与旋转到左侧的景观大约相差10度(ROTATION_0和ROTATION_180之间的差异较小,但仍然不同).这种差异足以破坏任何AR效应.

它与校准有关吗？ (我不相信我正在做正确的8件事 – 我尝试过在youtube上找到的各种方法).

任何想法为何有区别？我搞砸了旋转矩阵的东西吗？我可以选择将应用程序限制为单一方向,但仍然担心罗盘读数仍然不是很准确(即使过滤后它相当稳定)

public void onSensorChanged(SensorEvent event) {
        if (event.accuracy == SensorManager.SENSOR_STATUS_UNRELIABLE) {
            return;
        }

        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[] rotationMatrixA = mRotationMatrixA;
            if (SensorManager.getRotationMatrix(rotationMatrixA,null,mGravity,mGeomagnetic)) {

                float[] rotationMatrixB = mRotationMatrixB;

                display display = getwindowManager().getDefaultdisplay(); 
                int deviceRot = display.getRotation();

                switch (deviceRot)
                {
                // portrait - normal
                case Surface.ROTATION_0: SensorManager.remapCoordinateSystem(rotationMatrixA,SensorManager.AXIS_X,SensorManager.AXIS_Z,rotationMatrixB);
                break;
                // rotated left (landscape - keys to bottom)
                case Surface.ROTATION_90: SensorManager.remapCoordinateSystem(rotationMatrixA,SensorManager.AXIS_MINUS_X,rotationMatrixB); 
                break;
                // upside down
                case Surface.ROTATION_180: SensorManager.remapCoordinateSystem(rotationMatrixA,rotationMatrixB); 
                break;
                // rotated right
                case Surface.ROTATION_270: SensorManager.remapCoordinateSystem(rotationMatrixA,SensorManager.AXIS_MINUS_Z,rotationMatrixB); 
                break;

                default:  break;
                }

                float[] dv = new float[3]; 
                SensorManager.getorientation(rotationMatrixB,dv);
                // add to smoothing filter
                fd.AddLatest((double)dv[0]); 
            }
            mDraw.invalidate();     
        }
    }

public void onSensorChanged(SensorEvent event) {
    if (event.accuracy == SensorManager.SENSOR_STATUS_UNRELIABLE) {
        return;
    }

    if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER)  mGravity = event.values.clone ();
    if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) mGeomagnetic =  event.values.clone ();

    if (mGravity != null && mGeomagnetic != null) {

        float[] rotationMatrixA = mRotationMatrixA;
        if (SensorManager.getRotationMatrix(rotationMatrixA,mGeomagnetic)) {

            float[] rotationMatrixB = mRotationMatrixB;
            SensorManager.remapCoordinateSystem(rotationMatrixA,rotationMatrixB);
            float[] dv = new float[3]; 
            SensorManager.getorientation(rotationMatrixB,dv);
            // add to smoothing filter
            fd.AddLatest((double)dv[0]); 
        }
        mDraw.invalidate();     
    }
}

你不需要switch语句,似乎有很多关于getRotationMatrix,remapCoordinateSystem和来自stackoverflow问题的getorientation的混淆.我可能会在不久的将来写下这些的详细解释.