How to actualice the positions of the items in a googlemap?

Issue

i have a googlemap app that displays two items (itemizedoverlay class) and i have a Update button. When i press the update button, i want to remove the items from the map, and put again the same items but with the new latitude and longitude values (i have a service that actualice the latitude and longitude fields that i have in sharedPreferences, and also i recibe the other position by a bundle)

what i am doing wrong? when i try my code, the items of the map doesn't be removed.... just new items appear... but i want to remove the old ones

updateButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                mapOverlays.clear();
                updateMyPosition();
                updateFriendPosition();
            }
        });

and these are my two functions:

private void updateFriendPosition() 
    {
        Bundle bundle = this.getIntent().getExtras();//get the intent & bundle passed by X
        userText.setText(bundle.getString("user"));
        permissionText.setText(bundle.getString("permission"));
        lastUpdateText.setText(bundle.getString("lastupdate"));
        String coordinates[] = {bundle.getString("lat"), bundle.getString("lon")};  
        lat = Double.parseDouble(coordinates[0]);
        lng = Double.parseDouble(coordinates[1]);
        p = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
        OverlayItem overlayitem1 = new OverlayItem(p, bundle.getString("user"), "Hi Friend!");
        itemizedoverlay.addOverlay(overlayitem1);
        mapOverlays.add(itemizedoverlay);// dibujo la estrella con la posicion actual del friend

        mc.animateTo(p); ///nos centra el mapa en la posicion donde esta nuestro amigo
        mc.setZoom(10);  /// ajusta el zoom a 10        
    }

private void updateMyPosition()
    {
        String coordinates[] = {settings.getString("mylatitude", null),settings.getString("mylongitude", null)};    
        lat = Double.parseDouble(coordinates[0]);
        lng = Double.parseDouble(coordinates[1]);
        p = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
        OverlayItem overlayitem1 = new OverlayItem(p, "Me", "My Position");
        itemizedoverlay2.addOverlay(overlayitem1);
        mapOverlays.add(itemizedoverlay2);//dibujo mi icono para mostrarme a mi
    }

i also tryed with invalidate() on the mapview but it doesn't works... still paint the old items...

Solution

It looks like this is based on the SDK tutorial. You've added two things to itemizedoverlay and the other one. You need to add a method in HelloItemizedOverlay, namely 'clear'

public void clear() {
    mOverlays.clear();
}

Call this method before you call

itemizedoverlay.addOverlay(overlayitem1);

Answered By - NickT