Sensor.TYPE_ORIENTATION已弃用，不应使用。
阅读设备方向也让我有些头疼。这是我用于需要设备方向的活动的基类：
public abstract class SensorActivity extends Activity implements SensorEventListener {
private SensorManager sensorManager;
private final float[] accelerometerValues = new float[3];
private final float[] R = new float[9];
private final float[] I = new float[9];
private final float[] orientation = new float[3];
private final float[] remappedR = new float[9];
private final List<HasOrientation> observers = new ArrayList<HasOrientation>();
private int x;
private int y;
protected SensorActivity() {
this(SensorManager.AXIS_X, SensorManager.AXIS_Y);
}
/**
* Initializes a new instance.
*
*/
protected SensorActivity(int x, int y) {
setAxisMapping(x, y);
}
/**
* The parameters specify how to map the axes of the device to the axes of
* the sensor coordinate system.
*
* The device coordinate system has its x-axis pointing from left to right along the
* display, the y-axis is pointing up along the display and the z-axis is pointing
* upward.
*
* The <code>x</code> parameter defines the direction of the sensor coordinate system's
* x-axis in device coordinates. The <code>y</code> parameter defines the direction of
* the sensor coordinate system's y-axis in device coordinates.
*
* For example, if the device is laying on a flat table with the display pointing up,
* specify <code>SensorManager.AXIS_X</code> as the <code>x</code> parameter and
* <code>SensorManager.AXIS_Y</code> as the <code>y</code> parameter.
* If the device is mounted in a car in landscape mode,
* specify <code>SensorManager.AXIS_Z</code> as the <code>x</code> parameter and
* <code>SensorManager.AXIS_MINUS_X</code> as the <code>y</code> parameter.
*
* @param x specifies how to map the x-axis of the device.
* @param y specifies how to map the y-axis of the device.
*/
public void setAxisMapping(int x, int y) {
this.x = x;
this.y = y;
}
/**
* Registers an orientation observer.
*
* @param hasOrientation is the observer to register.
*/
protected void register(HasOrientation hasOrientation) {
observers.add(hasOrientation);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sensorManager = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
}
@Override
protected void onResume() {
super.onResume();
sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD), SensorManager.SENSOR_DELAY_UI);
sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_UI);
}
@Override
protected void onPause() {
sensorManager.unregisterListener(this);
super.onPause();
}
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
public void onSensorChanged(SensorEvent event) {
switch(event.sensor.getType())
{
case Sensor.TYPE_ACCELEROMETER:
System.arraycopy(event.values, 0, accelerometerValues, 0, accelerometerValues.length);
break;
case Sensor.TYPE_MAGNETIC_FIELD:
if (SensorManager.getRotationMatrix(R, I, accelerometerValues, event.values)) {
if (SensorManager.remapCoordinateSystem(R, x, y, remappedR)) {
SensorManager.getOrientation(remappedR, orientation);
for (HasOrientation observer : observers) {
observer.onOrientation(Orientation.fromRadians(orientation));
}
}
}
break;
default:
throw new IllegalArgumentException("unknown sensor type");
}
}
}
方向是这样的：
/**
* An angular direction vector.
*
* The vector consists of three angles {azimuth, pitch, roll}. Within a body-fixed
* cartesian system, the values of these angles define rotations of the three body axes.
*
* All angles are in degrees.
*
* @author michael@mictale.com
*
*/
public class Orientation {
/**
* Represents the angle to rotate the up axis.
*/
public float azimuth;
/**
* Represents the angle to rotate the axis pointing right.
*/
public float pitch;
/**
* Represents the angle to rotate the forward axis.
*/
public float roll;
/**
* Initializes an instance that is empty.
*/
public Orientation() {
}
/**
* Initializes an instance from the specified rotation values in degrees.
*
* @param azimuth is the azimuth angle.
* @param pitch is the pitch angle.
* @param roll is the roll angle.
*/
public Orientation(float azimuth, float pitch, float roll) {
this.azimuth = azimuth;
this.pitch = pitch;
this.roll = roll;
}
/**
* Sets the current values to match the specified orientation.
*
* @param o is the orientation to copy.
*/
public void setTo(Orientation o) {
this.azimuth = o.azimuth;
this.pitch = o.pitch;
this.roll = o.roll;
}
/**
* Normalizes the current instance.
*
* Limits the azimuth to [0...360] and pitch and roll to [-180...180].
*/
public void normalize() {
azimuth = Angle.normalize(azimuth);
pitch = Angle.tilt(pitch);
roll = Angle.tilt(roll);
}
/**
* Creates a new vector from an array of radian values in the form
* [azimuth, pitch, roll].
*
* This method is useful to fill sensor data into a vector.
*
* @param vec is the array of radians.
* @return the vector.
*/
public static Orientation fromRadians(float[] vec) {
return new Orientation((float)Math.toDegrees(vec[0]), (float)Math.toDegrees(vec[1]),
(float)Math.toDegrees(vec[2]));
}
@Override
public String toString() {
return "{a=" + azimuth + ", p=" + pitch + ", r=" + roll + "}";
}
}
您需要调用setAxisMapping()以接收与纵向或横向模式对齐的方向。我只在构造函数中调用它，所以我无法告诉你在活动运行时调用它会发生什么。您可能必须重置矩阵。