JRadioButton在JPanel,JPanel在JFrame上面，怎么捕捉事件

写了一个代码，一个JFrame( 称为 A )上面安装了一个 BorderLayout， 上面有4个JPanel，在其中的一个JPanel(称为 B)上面又有一个JPanel （称为 C ）, 我在C上面实现了 ActionListener 的 actionPerformed() 但是好像捉不到消息，大家帮我看看是怎么会回事啊，我把相关的代买贴上来了谢谢各位了// JPanle C 上面的public class VirtualWorldManagerSettingPanel extends JPanel implements
ActionListener { JLabel statue = new JLabel("off-line");

JRadioButton VisSimulation = new JRadioButton("Vis Simulation");
JRadioButton GenSimulation = new JRadioButton("Gen Simulation"); ButtonGroup group = new ButtonGroup();

public VirtualWorldManagerSettingPanel() { this.setBorder(BorderFactory
.createTitledBorder("Virtual World Manager"));
// this.setSize(new Dimension(400,200));

group.add(VisSimulation);
group.add(GenSimulation);

JPanel jp = new JPanel();
jp.setLayout(new GridLayout(2, 0));

jp.add(VisSimulation);
jp.add(GenSimulation);

GenSimulation.setSelected(true);

this.add(jp); } @Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
if( arg0.getSource().equals("Vis Simulation")){
System.out.println("Vis Simulation");
}

if( arg0.getSource().equals("Gen Simulation")){
System.out.println("Vis Simulation");
}
}}// JPanle B 和 JFrame 都写在一起了public class MASSimulator extends JFrame { private static MASSimulator INSTANCE; // panels that are the basical layout of main frame
private JPanel North; // the panels that private VirtualWorldManagerSettingPanel vwmsp = new VirtualWorldManagerSettingPanel(); private MASSimulator() { this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); }
private void buildInterface() { this.buildNorthPanel();
} private void buildNorthPanel() {
this.North = new JPanel();
this.North.add(this.vwmsp); this.add(this.North, BorderLayout.NORTH);
}
@Override
protected void processWindowEvent(WindowEvent e) { if (e.getID() == WindowEvent.WINDOW_CLOSING) { Calendar cal = Calendar.getInstance();
String name = cal.getTime().getHours() + "_"
+ cal.getTime().getMinutes() + "_"
+ cal.getTime().getSeconds(); ProcessLogStorage.getInstance().saveSimulationLogAsXML(
"./Logs/" + name + ".mxml");
} super.processWindowEvent(e); } public static MASSimulator getInstance() {
if (INSTANCE == null) {
INSTANCE = new MASSimulator();
}
return INSTANCE;
} public static void main(String[] arg) {
getInstance().setVisible(true);
}}