我已经深入了解了这一点,在谷歌感觉要更新他们的代码之前是不可能做到的。
相反,我已经创建了自己的类,它为我绘制了位置——可以随时更新。
代码在这里。
/**
*
* @author (hwrdprkns)
* 2010
*
*/
public class CenterOverlay extends ItemizedOverlay<OverlayItem> implements LocationListener {
private static final String TAG = "CenterOverlay: ";
private LocationManager mLocationManager;
private long updateTime = 60000;
private static final int updateDistance = 50;
private GeoPoint lastKnownPoint;
private Location lastKnownLocation;
private Drawable centerDrawable;
private Context mContext;
private final List<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
private Paint accuracyPaint;
private Point center;
private Point left;
private Drawable drawable;
private int width;
private int height;
// San Francisco
private final static double[] DEFAULT_LOCATION = {
37.7749295, -122.4194155
};
private Runnable firstFixRunnable = null;
private boolean firstFixRun = false;
public CenterOverlay(Drawable defaultMarker, MapView mapView, Context c) {
super(boundCenter(defaultMarker));
this.centerDrawable = defaultMarker;
this.mContext = c;
mLocationManager = (LocationManager) c.getSystemService(Context.LOCATION_SERVICE);
if (Constants.DEBUG) {
updateTime = 0;
} else {
updateTime = 60000;
}
}
public void addOverlay(OverlayItem overlay) {
mOverlays.add(overlay);
populate();
}
private void checkFirstRunnable() {
if (!firstFixRun && lastKnownLocation != null && firstFixRunnable != null) {
firstFixRunnable.run();
}
}
private OverlayItem createCenterOverlay(GeoPoint point) {
OverlayItem i = new OverlayItem(point, "Location", null);
i.setMarker(centerDrawable);
return i;
}
private GeoPoint createGeoPoint(Location loc) {
int lat = (int) (loc.getLatitude() * 1E6);
int lng = (int) (loc.getLongitude() * 1E6);
return new GeoPoint(lat, lng);
}
@Override
protected OverlayItem createItem(int i) {
return mOverlays.get(i);
}
public void disableLocation() {
mLocationManager.removeUpdates(this);
}
@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow) {
drawMyLocation(canvas, mapView, lastKnownLocation, lastKnownPoint, 0);
}
protected void drawMyLocation(Canvas canvas, MapView mapView, Location lastFix, GeoPoint myLoc,
long when) {
accuracyPaint = new Paint();
accuracyPaint.setAntiAlias(true);
accuracyPaint.setStrokeWidth(2.0f);
drawable = centerDrawable;
width = drawable.getIntrinsicWidth();
height = drawable.getIntrinsicHeight();
center = new Point();
left = new Point();
Projection projection = mapView.getProjection();
double latitude = lastFix.getLatitude();
double longitude = lastFix.getLongitude();
float accuracy = lastFix.getAccuracy();
float[] result = new float[1];
Location.distanceBetween(latitude, longitude, latitude, longitude + 1, result);
float longitudeLineDistance = result[0];
GeoPoint leftGeo = new GeoPoint((int) (latitude * 1e6), (int) ((longitude - accuracy
/ longitudeLineDistance) * 1e6));
projection.toPixels(leftGeo, left);
projection.toPixels(myLoc, center);
int radius = center.x - left.x;
accuracyPaint.setColor(0xff6666ff);
accuracyPaint.setStyle(Style.STROKE);
canvas.drawCircle(center.x, center.y, radius, accuracyPaint);
accuracyPaint.setColor(0x186666ff);
accuracyPaint.setStyle(Style.FILL);
canvas.drawCircle(center.x, center.y, radius, accuracyPaint);
drawable.setBounds(center.x - width / 2, center.y - height / 2, center.x + width / 2,
center.y + height / 2);
drawable.draw(canvas);
}
public void enableMyLocation() {
for (String s : mLocationManager.getProviders(true)) {
mLocationManager.requestLocationUpdates(s, updateTime, updateDistance, this);
}
Location loc = null;
for (String s : mLocationManager.getProviders(true)) {
loc = mLocationManager.getLastKnownLocation(s);
if (loc != null) {
loc.setLatitude(DEFAULT_LOCATION[0]);
loc.setLongitude(DEFAULT_LOCATION[1]);
lastKnownLocation = loc;
lastKnownPoint = createGeoPoint(loc);
return;
}
}
loc = new Location(LocationManager.GPS_PROVIDER);
loc.setLatitude(DEFAULT_LOCATION[0]);
loc.setLongitude(DEFAULT_LOCATION[1]);
lastKnownLocation = loc;
lastKnownPoint = createGeoPoint(loc);
}
public Location getLastKnownLocation() {
return lastKnownLocation;
}
public GeoPoint getLastKnownPoint() {
return lastKnownPoint;
}
public void onLocationChanged(Location location) {
checkFirstRunnable();
this.lastKnownLocation = location;
this.lastKnownPoint = createGeoPoint(location);
replaceOverlay(createCenterOverlay(lastKnownPoint));
}
public void onProviderDisabled(String provider) {
ViewAdapter.showLongToast(mContext,
"Your location provider has been disabled -- please reenable it");
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
if (status == LocationProvider.AVAILABLE) {
}
if (status == LocationProvider.OUT_OF_SERVICE) {
ViewAdapter.showShortToast(mContext, "Location is temporarily out of service.");
}
if (status == LocationProvider.TEMPORARILY_UNAVAILABLE) {
}
}
private void replaceOverlay(OverlayItem overlay) {
mOverlays.clear();
mOverlays.add(overlay);
populate();
}
public boolean runOnFirstFix(Runnable runnable) {
if (lastKnownLocation != null) {
runnable.run();
return true;
}
firstFixRunnable = runnable;
return false;
}
@Override
public int size() {
return mOverlays.size();
}
public void updateLocation() {
}
}
