Dynamically create a button, but what happened?

Question

I am new to Swing GUI, and I want to create a new button in a panel named centerPanel, so my code like this:
public class TestButton extends JFrame {
     public static void main(String args[]) {
          try {
               TestButton frame = new TestButton();
               frame.setVisible(true);
          } catch (Exception e) {
               e.printStackTrace();
     public TestButton() {
          super();
          setBounds(100, 100, 500, 375);
          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          final JPanel center = new JPanel();
          getContentPane().add(center, BorderLayout.CENTER);
          final JPanel south = new JPanel();
          getContentPane().add(south, BorderLayout.SOUTH);
          final JButton button = new JButton();
          button.addActionListener(new ActionListener() {
               public void actionPerformed(final ActionEvent arg0) {
                    JButton newbutton = new JButton("Heeeeeeeee");
                    center.add(newbutton);
                    center.repaint();
          button.setText("New JButton");
          south.add(button);
}but why this does not work, I can not see it? Please give me a hand, thanks in advance!

Answer 1

Call center.revalidate () after add (...), not center.repaint ().
db
edit Just noticed who the question was addressed to, thought I'd clarify that I'm not really authorized to answer on His behalf.
Edited by: Darryl.Burke