static class MapOverlay extends com.google.android.maps.Overlay {
        @Override
        public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when) {
            super.draw(canvas, mapView, shadow);
            Point screenPoints_currentLoc = new Point();
            Point screenPoints_currentStationLoc = new Point();
            // Geokoordinaten in Bildschirmkoordinaten umwandeln
            mapView.getProjection().toPixels(currentLoc, screenPoints_currentLoc);
            mapView.getProjection().toPixels(currentStationLoc, screenPoints_currentStationLoc);
            // Verbindungslinie zwischen den Orten
            if (showLine) {
                Paint lineStyle = new Paint();
                lineStyle.setColor(Color.YELLOW);
                lineStyle.setStyle(Style.FILL_AND_STROKE);
                lineStyle.setStrokeWidth(3);
                canvas.drawLine(screenPoints_currentLoc.x, screenPoints_currentLoc.y, screenPoints_currentStationLoc.x, screenPoints_currentStationLoc.y, lineStyle);
            }
            // Marker erstellen
            Bitmap currentLocMarker = BitmapFactory.decodeResource(res, R.drawable.gmarker_green);
            Bitmap currentStationLocMarker = BitmapFactory.decodeResource(res, R.drawable.gmarker_red);
            // Marker setzen
            canvas.drawBitmap(currentLocMarker, screenPoints_currentLoc.x - halfPicWidth, screenPoints_currentLoc.y - PicHeight, null);
            canvas.drawBitmap(currentStationLocMarker, screenPoints_currentStationLoc.x - halfPicWidth, screenPoints_currentStationLoc.y - PicHeight, null);
            return true;
        }
    }

                MapOverlay markers = new MapOverlay();
                List<Overlay> listOfMarkers = mapView.getOverlays();
                listOfMarkers.clear();
                listOfMarkers.add(markers);