我正在使用 Android 地图，我需要在其中添加指南针功能，即当我单击指南针按钮时，它会显示单独的指南针。任何人都可以指导我正确的方向或参考任何教程。我需要单独添加 Compass 提前感谢阅读和回复
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1
我的 Cass 中的场景是单独使用使用指南针点击指南针按钮时它会显示
- 从当前位置（我的位置）到目标位置的距离
- 罗盘
- 指南针朝北方向所以为了实现所有这些，我使用了以下方法希望这将帮助任何与我有相同情况的人
我的班级的代码片段将获得全球两点之间的距离并将图像显示为指南针，头朝北
public class MapController extends MapActivity implements SensorEventListener {
public static GeoPoint Mypoint, MapPoint;
double km, meter;
public static int kmInDec, meterInDec;
private SensorManager mSensorManager;
private Sensor mAccelerometer, mField;
Location myLoc, mapLoc;
double myLat, myLong, mapLat, mapLong;
public static double lat, lng;
public static double mylat = Double.parseDouble(Constants.DEVICE_OBJ.lat);//31.567615d;
public static double mylon = Double.parseDouble(Constants.DEVICE_OBJ.lng);//74.360962d;
com.google.android.maps.MapController mapController;
public static boolean enabled = false;
@Override
protected void onCreate(Bundle icicle) {
// TODO Auto-generated method stub
super.onCreate(icicle);
setContentView(R.layout.map_layout);
Log.v(Constants.TAG, "In Map Controller");
fetchUI();
}
public void fetchUI() {
myLoc = new Location("Test");
mapLoc = new Location("Test");
mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mField = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
myLat = (31.567615 * 1e6) / 1E6;
myLong = (74.360962d * 1e6) / 1E6;
mapLat = (MapPoint.getLatitudeE6()) / 1E6;
mapLong = (MapPoint.getLongitudeE6()) / 1E6;
myLoc.setLatitude(31.567615);
myLoc.setLongitude(74.360962);
mapLoc.setLatitude(mapLat);
mapLoc.setLongitude(mapLong);
}
protected void onResume() {
super.onResume();
mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_UI);
mSensorManager.registerListener(this, mField, SensorManager.SENSOR_DELAY_UI);
}
protected void onPause() {
super.onPause();
mSensorManager.unregisterListener(this);
}
@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
///Method to calculate the Distance between 2 Geo Points aroud the Globe
public double CalculationByDistance(GeoPoint StartP, GeoPoint EndP) {
double lat1 = StartP.getLatitudeE6() / 1E6;
double lat2 = EndP.getLatitudeE6() / 1E6;
double lon1 = StartP.getLongitudeE6() / 1E6;
double lon2 = EndP.getLongitudeE6() / 1E6;
double dLat = Math.toRadians(lat2 - lat1);
double dLon = Math.toRadians(lon2 - lon1);
double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
Math.sin(dLon / 2) * Math.sin(dLon / 2);
double c = 2 * Math.asin(Math.sqrt(a));
double valueResult = Radius * c;
double km = valueResult / 1;
DecimalFormat newFormat = new DecimalFormat("####");
kmInDec = Integer.valueOf(newFormat.format(km));
meter = valueResult % 1000;
meterInDec = Integer.valueOf(newFormat.format(meter));
Log.i("Radius Value", "" + valueResult + " KM " + kmInDec + " Meter " + meterInDec);
return Radius * c;
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// TODO Auto-generated method stub
}
@Override
public void onSensorChanged(SensorEvent event) {
// TODO Auto-generated method stub
if (myLoc == null) return;
float azimuth = event.values[0];
float baseAzimuth = azimuth;
GeomagneticField geoField = new GeomagneticField(Double
.valueOf(myLoc.getLatitude()).floatValue(), Double
.valueOf(myLoc.getLongitude()).floatValue(),
Double.valueOf(myLoc.getAltitude()).floatValue(),
System.currentTimeMillis());
azimuth -= geoField.getDeclination(); // converts magnetic north into true north
// Store the bearingTo in the bearTo variable
float bearTo = myLoc.bearingTo(mapLoc);
// If the bearTo is smaller than 0, add 360 to get the rotation clockwise.
if (bearTo < 0) {
bearTo = bearTo + 360;
}
//This is where we choose to point it
float direction = bearTo - azimuth;
// If the direction is smaller than 0, add 360 to get the rotation clockwise.
if (direction < 0) {
direction = direction + 360;
}
rotateImageView(compasView, R.drawable.app_icon, direction);
//Set the field
String bearingText = "N";
if ((360 >= baseAzimuth && baseAzimuth >= 337.5) || (0 <= baseAzimuth && baseAzimuth <= 22.5))
bearingText = "N";
else if (baseAzimuth > 22.5 && baseAzimuth < 67.5) bearingText = "NE";
else if (baseAzimuth >= 67.5 && baseAzimuth <= 112.5) bearingText = "E";
else if (baseAzimuth > 112.5 && baseAzimuth < 157.5) bearingText = "SE";
else if (baseAzimuth >= 157.5 && baseAzimuth <= 202.5) bearingText = "S";
else if (baseAzimuth > 202.5 && baseAzimuth < 247.5) bearingText = "SW";
else if (baseAzimuth >= 247.5 && baseAzimuth <= 292.5) bearingText = "W";
else if (baseAzimuth > 292.5 && baseAzimuth < 337.5) bearingText = "NW";
else bearingText = "?";
Distance.setText(kmInDec + " Km " + " " + meterInDec + " m");
}
////This is the method to Show the Image as Compass
private void rotateImageView(ImageView imageView, int drawable, float rotate) {
// Decode the drawable into a bitmap
Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
drawable);
// Get the width/height of the drawable
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
int width = bitmapOrg.getWidth(), height = bitmapOrg.getHeight();
// Initialize a new Matrix
Matrix matrix = new Matrix();
// Decide on how much to rotate
rotate = rotate % 360;
// Actually rotate the image
matrix.postRotate(rotate, width, height);
// recreate the new Bitmap via a couple conditions
Bitmap rotatedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0, width, height, matrix, true);
//BitmapDrawable bmd = new BitmapDrawable( rotatedBitmap );
//imageView.setImageBitmap( rotatedBitmap );
imageView.setImageDrawable(new BitmapDrawable(getResources(), rotatedBitmap));
imageView.setScaleType(ScaleType.CENTER);
}
}
于 2013-01-17T05:17:33.170 回答
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于 2013-01-16T11:32:53.790 回答