android-maps-Kreis overlay, dynamisch ändern Sie den radius?

Ich habe eine MapView in meiner app und bin Zeichnung ein paar Kreis-overlays auf der Karte. Alles ist in Ordnung, aber wenn ich den zoom auf der Karte, die overlay-radius nicht ändert. Ich habe versucht, auf der Suche in Foren und google nach einer Lösung aber konnte nicht finden, eine, die arbeitete für mich. Hat jemand irgendwelche Ideen?

Hier ist mein code:

HelloGoogleMaps.java (Haupttätigkeit)

package com.adam.maps;

import java.util.Iterator;
import java.util.List;

import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.AbsoluteLayout;
import android.widget.RelativeLayout;
import android.widget.Toast;
import android.widget.ZoomButtonsController.OnZoomListener;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;

public class HelloGoogleMaps extends MapActivity {  
//create new LocationManager
//and LocationListener objects
LocationManager lm;
LocationListener locationListener;

OnZoomListener listener;

//create a new MapView
//and MapController object
MapView mapView;
MapController mc;

RelativeLayout parent;

int num = 4;
//LoopRegion region[] = new LoopRegion[num];
//LoopRegion border[] = new LoopRegion[num];
float regionX[] = {(float) 42.91556645193364, (float) 42.9151598328247, 
        (float) 43.00110298764482, (float) 43.00054196511636};
float regionY[] = {(float) -78.87073255078127, (float) -78.8714594294243, 
        (float) -78.78354466454317, (float) -78.78226256863405};
int regionR[] = {100, 70, 150, 75};
GeoPoint regionC[] = new GeoPoint[num];
CustomOverlay overlay[] = new CustomOverlay[num];
CustomOverlay overlayLoc;


/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Toast.makeText(getBaseContext(), 
            "Welcome to 'sound clusters'" , 
            Toast.LENGTH_LONG).show();

    //---use the LocationManager class to obtain GPS locations---
    lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);    

    locationListener = new MyLocationListener();

    lm.requestLocationUpdates(
        LocationManager.GPS_PROVIDER, 
        0, 
        0, 
        locationListener);

    //set our mapViewer object to our "mapview" namespace in the xml layout file
    //this allows us to set the zoom control "ON" in our view
    mapView = (MapView) findViewById(R.id.mapview);
    //this will enable zoom controls, and put it on the screen
    mapView.setBuiltInZoomControls(true);
    //--------------------------------------------------------//
    parent = (RelativeLayout) findViewById(R.id.parent);

    //-------this is part of creating an overlay icon-------------------------------
    /*List<Overlay> mapOverlays = mapView.getOverlays();
    Drawable drawable = this.getResources().getDrawable(R.drawable.icon);
    CustomItemizedOverlay itemizedOverlay =
        new CustomItemizedOverlay(drawable, this);*/
    //------------------------------------------------------------------------------

    //Create new Overlay
    for (int i = 0; i < num; i++){
        regionC[i] = new GeoPoint(
                (int) (regionX[i] * 1E6), 
                (int) (regionY[i] * 1E6));
        int newRadius = (int) feetToPixels(mapView.getZoomLevel(), regionR[i]);
        overlay[i] = new CustomOverlay(regionC[i], newRadius);
        mapView.getOverlays().add(overlay[i]);
    }

    //-------this is part of creating an overlay icon-------------------------------
    /*OverlayItem overlayitem =
         new OverlayItem(point, "Hello", "I'm in Athens, Greece!");
    itemizedOverlay.addOverlay(overlayitem);
    mapOverlays.add(itemizedOverlay);*/
    //------------------------------------------------------------------------------



    mc = mapView.getController();
    mc.setZoom(20);
    mapView.setSatellite(true);
    Toast.makeText(getBaseContext(), 
            "Zoom level: " + mapView.getZoomLevel(), 
            Toast.LENGTH_SHORT).show();


}

//not sure what this does, but Google says you need it----//
@Override
protected boolean isRouteDisplayed() {
    return false;
}
//--------------------------------------------------------//   

private class MyLocationListener implements LocationListener 
{

    //@Override
    public void onLocationChanged(Location loc) {
        if (loc != null) {

            List overlays = mapView.getOverlays();
            //first remove old overlay
            if (overlays.size() > 0) {
                for (Iterator iterator = overlays.iterator(); iterator
                        .hasNext();) {
                    iterator.next();
                    iterator.remove();
                }
            }

            GeoPoint p = new GeoPoint(
                    (int) (loc.getLatitude() * 1E6), 
                    (int) (loc.getLongitude() * 1E6));

            overlayLoc = new CustomOverlay(p, 5);
            mapView.getOverlays().add(overlayLoc);
            for (int i = 0; i < num; i++){
                mapView.getOverlays().add(overlay[i]);
            }
            //mc.animateTo(p);
            //mc.setZoom(16);
            mapView.invalidate();
        }
    }

    //@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
    }
}

//custom functions--------------------------------------------------------------------
private static final double equatorFeet = 131479920; 
private double feetToPixels(int zoomLevel, int feet) { 
    double equatorPixels = 256; 
    for (int i = 1; i < zoomLevel; i++) { 
        equatorPixels = equatorPixels * 2; 
    } 
    double pixelPerFoot = equatorPixels / equatorFeet; 
    return feet * pixelPerFoot; 
} 
//------------------------------------------------------------------------------------

}

Und die Overlay-Klasse CustomOverlay.java

package com.adam.maps;

import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
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 CustomOverlay extends Overlay {

private GeoPoint geopoint;
private int rad;

public CustomOverlay(GeoPoint point, int radius) {
    geopoint = point;
    rad = radius;
}


@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow) {
    //Transform geo-position to Point on canvas
    Projection projection = mapView.getProjection();
    Point point = new Point();
    //store the transformed geopoint into a point with pixel values
    projection.toPixels(geopoint, point);

    /*//text "My Location"
    Paint text = new Paint();
    text.setAntiAlias(true);
    text.setColor(Color.BLUE);
    text.setTextSize(12);
    text.setTypeface(Typeface.MONOSPACE);*/

    //the circle to mark the spot
    Paint circlePaint = new Paint();
    circlePaint.setAntiAlias(true);
    //fill region
    circlePaint.setColor(Color.RED);
    circlePaint.setAlpha(90);
    circlePaint.setStyle(Paint.Style.FILL);
    canvas.drawCircle(point.x, point.y, rad, circlePaint);
    //border region
    circlePaint.setColor(Color.WHITE);
    circlePaint.setAlpha(255);
    circlePaint.setStyle(Paint.Style.STROKE);
    circlePaint.setStrokeWidth(3);
    canvas.drawCircle(point.x, point.y, rad, circlePaint);

    /*canvas.drawText("My Location", point.x + 3 * CIRCLERADIUS, point.y + 3
            * CIRCLERADIUS, text);*/
}
}

Vielen Dank im Voraus für Eure Hilfe!

InformationsquelleAutor Adam | 2011-04-19