Why btnRefresh can't response to the button click after first time?

Question

package javaapplication14;

import javax.swing.JFrame;

/**
*
* @author xuji28
*/
public class JavaApplication14 {

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
new JMainFrame();
}

}

package javaapplication14;

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;

/**
*
* @author xuji28
*/
public class JMainFrame {
JFrame mainFrm=null;
JButton btn=null;
int i=0;
JPanelTest panel=null;
public JMainFrame()
{
mainFrm=new JFrame("Test");
mainFrm.setLayout(new GridLayout(2,1));
btn=new JButton("OK");
btn.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
btn.setText("counts: "+String.valueOf(i++));
}

});
mainFrm.add(btn);
panel=new JPanelTest();
mainFrm.add(panel.getPanel());
mainFrm.setSize(100, 50);
mainFrm.pack();
mainFrm.setVisible(true);
}
}
package javaapplication14;

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JPanel;

/**
*
* @author xuji28
*/
public class JPanelTest{
JPanel panel=null;//new JPanel();
JButton btnRefresh=null;

int i=0;
public JPanel getPanel()
{
btnRefresh=new JButton("Refresh");
btnRefresh.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent agr0) {
btnRefresh.setText("clicked:"+String.valueOf(i));//???Why btnRefresh can't
//response to the button click?
}
});
panel=new JPanel();
panel.add(btnRefr

Answer 1

if i recall correctly, if you are changing name of button you should call frame#validate and frame#repaint try these.