我正在尝试在地图中显示我当前的位置以及地址。下面的代码工作正常，但不知何故我无法在我当前的位置周围绘制或指向一个圆圈。任何帮助将不胜感激。我使用的是旧 API。
这是我的主要课程。
public class GMapsActivity extends MapActivity implements LocationListener {
private static final String TAG = "LocationActivity";
private static GMapsActivity instance;
private MapView mapView;
protected LocationManager locationManager;
public Button retrieveLocationButton;
Geocoder geocoder;
TextView locationText;
Location location;
MapController mapController;
CountDownTimer locationtimer;
// private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
// private static final long MINIMUM_TIME_BETWEEN_UPDATES = 9000; // in Milliseconds
// MapOverlay mapOverlay = new MapOverlay();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_gmaps);
mapView = (MapView) findViewById(R.id.map_view);
mapView.setBuiltInZoomControls(true);
locationText = (TextView)this.findViewById(R.id.lblLocationInfo);
mapController = mapView.getController();
mapController.setZoom(13);
retrieveLocationButton = (Button) findViewById(R.id.retrieve_location_button);
}
public void showcurrentlocation(View view) {
geocoder = new Geocoder(GMapsActivity.this);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
mapView.getOverlays().add(new CircleOverlay(this, location.getLatitude(),location.getLongitude(),325));
if (location != null) {
Log.d(TAG, location.toString());
this.onLocationChanged(location); //<6>
}
}
@Override
public void onLocationChanged(Location location) {
Log.d(TAG, "onLocationChanged with location " + location.toString());
String text = String.format("Lat:\t %f\nLong:\t %f\nAlt:\t %f\nBearing:\t %f", location.getLatitude(),location.getLongitude(), location.getAltitude(),
location.getBearing());
this.locationText.setText(text);
try {
List<Address> addresses = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 10); //<10>
for (Address address : addresses) {
this.locationText.append("\n" + address.getAddressLine(0));
}
int latitude = (int)(location.getLatitude() * 1000000);
int longitude = (int)(location.getLongitude() * 1000000);
GeoPoint point = new GeoPoint(latitude,longitude);
mapController.animateTo(point); //<11>
}
catch (IOException e) {
Log.e("LocateMe", "Could not get Geocoder data", e);
}
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status,Bundle extras) {
// TODO Auto-generated method stub
}
// @Override protected void onResume() {
// LocationListener locationListener = new LocationListener(){
// super.onResume();
// locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 10, this); //<7>
// }
// @Override protected void onPause() {
// super.onPause();
// locationManager.removeUpdates(this); //<8>
//
// }
@Override
protected boolean isRouteDisplayed() {
return false;
}
}
下面是我的圈课。
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.util.FloatMath;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.Projection;
public class CircleOverlay extends Overlay {
Context context;
double mLat;
double mLon;
float mRadius;
public CircleOverlay(Context _context, double _lat, double _lon, float radius ) {
context = _context;
mLat = _lat;
mLon = _lon;
mRadius = radius;
}
public void draw(Canvas canvas, MapView mapView, boolean shadow) {
super.draw(canvas, mapView, shadow);
if(shadow) return; // Ignore the shadow layer
Projection projection = mapView.getProjection();
Point pt = new Point();
GeoPoint geo = new GeoPoint((int) (mLat *1e6), (int)(mLon * 1e6));
projection.toPixels(geo ,pt);
float circleRadius = projection.metersToEquatorPixels(mRadius) * (1/ FloatMath.cos((float) Math.toRadians(mLat)));
Paint innerCirclePaint;
innerCirclePaint = new Paint();
innerCirclePaint.setColor(Color.BLUE);
innerCirclePaint.setAlpha(25);
innerCirclePaint.setAntiAlias(true);
innerCirclePaint.setStyle(Paint.Style.FILL);
canvas.drawCircle((float)pt.x, (float)pt.y, circleRadius, innerCirclePaint);
}
}