Ecco un esempio:
codice:
import java.awt.event.WindowEvent;
import java.awt.event.WindowAdapter;
import javax.swing.*;
public class FrameTest extends JFrame
{
public FrameTest ()
{
super ("Frame Test");
setDefaultCloseOperation (JFrame.DO_NOTHING_ON_CLOSE);
setSize (300, 300);
addWindowListener (new CloseWarning ());
}
public static void main (String[] args)
{
FrameTest f = new FrameTest ();
f.setVisible (true);
}
class CloseWarning extends WindowAdapter
{
public void windowClosing (WindowEvent e)
{
int ret = JOptionPane.showConfirmDialog (FrameTest.this, "Chiudere la finestra?",
"Frame Test", JOptionPane.YES_NO_OPTION);
if (ret == JOptionPane.YES_OPTION)
System.exit (0);
}
}
}