如何在MyLocationOverlay中为"你在这里"点使用自定义位图？

public class CustomMyLocationOverlay extends MyLocationOverlay {

    private Bitmap customBitmap;

    public CustomMyLocationOverlay(Context context, MapView mapView) {
        super(context, mapView);
        customBitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.custom_location_icon);
    }

    @Override
    protected void onDraw(Canvas canvas, MapView mapView, boolean shadow, long when) {
        super.onDraw(canvas, mapView, shadow, when);
        if (getMyLocation() != null) {
            Point point = new Point();
            mapView.getProjection().toPixels(getMyLocation(), point);
            canvas.drawBitmap(customBitmap, point.x - customBitmap.getWidth() / 2, point.y - customBitmap.getHeight(), null);
        }
    }
}

CustomMyLocationOverlay myLocationOverlay = new CustomMyLocationOverlay(this, mapView);
mapView.getOverlays().add(myLocationOverlay);
myLocationOverlay.enableMyLocation();