Update JFrame including JComboBox

Question

Hello,
Read lots about this stuff, but nothing worked in my case...
Here more about my problem:
In my JFrame , there's a JComboBox which contains several names of people.
I can open a JInternalFrame , where I can add an extra name.
When I close the JInternalFrame, the main JFrame (incl the JComboBox ) has to update, so the extra name is visible...
private class InternalFrameHandler extends InternalFrameAdapter{
        public void internalFrameClosing(InternalFrameEvent e){
                if(e.getSource()==userFrame){
                    updateFrame();
public void updateFrame(){
        this.repaint();
        this.validate();
    }It doesn't works. I've tried also:
- getContentPane().repaint() and then getContentPane().validate();
or
- this.update(getContentPane().getGraphics());
None of this seems to work...
Strange,
Any ideas?
Thank you

Answer 1

Extra class info: ( simplified )
public class GUI extends JFrame{
     private JDesktopPane desktop;
     private JComboBox keuzeGebruiker;
     private JInternalFrame userFrame;
public GUI(String title, int breedte, int hoogte) {
        super(title);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setExtendedState(JFrame.MAXIMIZED_BOTH);
        this.setResizable(false);
        this.setUndecorated(false);
        this.breedte=breedte;
        this.hoogte=hoogte;
        desktop = new JDesktopPane();
        desktop.setLayout(new BorderLayout(0,0));
        setContentPane(desktop);
        desktop.setBackground(kleur.getBackground());
        keuzeGebruiker = new JComboBox(lijstGebruikers);
        keuzeGebruiker.setSelectedItem(null);
        keuzeGeb = new JPanel();
        keuzeGeb.setLayout(new FlowLayout(1,breedte/80,hoogte/100));
        keuzeGeb.add(keuzeGebruiker);
      desktop.add(logIn,"North");
        addWindowListener(new WindowHandler());
}