Android GoogleMap Overlay （图层标记）

写一个类继承ItemizedOverlay
package cn.fn;

import java.util.ArrayList;
import android.app.AlertDialog;
import android.content.Context;
import android.graphics.drawable.Drawable;
import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.OverlayItem;

public class CustomItemizedOverlay extends ItemizedOverlay<OverlayItem> {

private ArrayList<OverlayItem> mapOverlays = new ArrayList<OverlayItem>();
private Context context;

public CustomItemizedOverlay(Drawable defaultMarker) {
super(boundCenterBottom(defaultMarker));
}

public CustomItemizedOverlay(Drawable defaultMarker, Context context) {
this(defaultMarker);
this.context = context;
}

@Override
protected OverlayItem createItem(int i) {
return mapOverlays.get(i);
}

@Override
public int size() {
return mapOverlays.size();
}

@Override
protected boolean onTap(int index) {
OverlayItem item = mapOverlays.get(index);
AlertDialog.Builder dialog = new AlertDialog.Builder(context);
dialog.setTitle(item.getTitle());
dialog.setMessage(item.getSnippet());
dialog.show();
return true;
}

public void addOverlay(OverlayItem overlayItem) {
mapOverlays.add(overlayItem);
this.populate();
}

}


MainActivity  取MapView 进行设置

package cn.fn;

import java.util.List;

import android.graphics.drawable.Drawable;
import android.os.Bundle;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;


public class TextActivity extends MapActivity {
   
    private MapView mapView;

    private static final int lat1 = 39984881;
    private static final int lon1 = 116337044;

    private static final int lat2 = 39977293;
    private static final int lon2 = 116353089;
   
    @Override
    public void onCreate(Bundle savedInstanceState) {
       
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        mapView = (MapView) findViewById(R.id.myMapView); 
        mapView.setStreetView(true);
        mapView.setTraffic(true);
        mapView.setBuiltInZoomControls(true);
       
        List<Overlay> mapOverlays = mapView.getOverlays();
        Drawable drawable = this.getResources().getDrawable(R.drawable.hua);
        CustomItemizedOverlay itemizedOverlay = new CustomItemizedOverlay(drawable, this);
       
        itemizedOverlay.addOverlay(new OverlayItem(new GeoPoint(lat1, lon1), "HaHa", "HaHa"));
        itemizedOverlay.addOverlay(new OverlayItem(new GeoPoint(lat2, lon2), "HaHa", "HaHa"));
        mapOverlays.add(itemizedOverlay);
       
        MapController mapController = mapView.getController();
        //定位到显示的位置
        mapController.animateTo(new GeoPoint(locallat, locallon));
        mapController.setZoom(15);
       
    }

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }
   
}



提示：这个现在还有一个问题就是加太多的话就会