KeyListener no longer working in JPanel

Question

Hi,
I have implemented a graphics interface with JPanel with mouse action and movement captured. Everything works fine until I added KeyListener implementation.
No matter what I do, I could not enable the key event.
The top window is a JFrame which contains several components and one of them is a JPanel. I wanted to capture key event inside that JPanel.
JFrameC a = new JFrameC();
JPanelC b = new JPanelC(a);
And inside JPanelC, I have statement as
a.addKeyListener(this);
addKeyListener(this);
But still no key event.
If I simply change JPanelC class from JPanel to Panel (only extends statement), key event appears as it supposes to be.
What's wrong with JPanel? I thought it should behave similar to Panel with more better features.
What should I do to enable key event in JPanel?
Please help.

Answer 1

I tried the following simple program which is similar to my complicated implementation and it worked. I am confused.
<pre>
//KeyFrame.java
import javax.swing.*;
import java.awt.event.*;
import java.awt.BorderLayout;
import java.awt.*;
public class KeyFrame extends JFrame {
public KeyFrame(String s) {
super(s);
KeyEventDemo ked = new KeyEventDemo(this);
getContentPane().add(ked);
pack();
show();
setSize(500, 500);
validate();
public static void main(String [] args) {
KeyFrame kf = new KeyFrame("");
// KeyEventDemo.java
import javax.swing.*;
import java.awt.event.*;
import java.awt.BorderLayout;
import java.awt.*;
public class KeyEventDemo extends JPanel
//implements KeyListener, ActionListener {
implements KeyListener {
public KeyEventDemo(Component c) {
super();
c.addKeyListener(this);
//addKeyListener(this);
/** Handle the key typed event from the text field. */
public void keyTyped(KeyEvent e) {
System.err.println("KEY TYPED: ");
/** Handle the key pressed event from the text field. */
public void keyPressed(KeyEvent e) {
System.err.println("KEY PRESSED: ");
/** Handle the key released event from the text field. */
public void keyReleased(KeyEvent e) {
System.err.println("KEY RELEASED: ");
</pre>