jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Question

  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//这个方法，我想在调用这个方法之前需要做一些事情，请问怎么搞？

Answer 1

import javax.swing.*;public class Test extends JFrame
{
public Test()
{
pack();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Runtime.getRuntime().addShutdownHook(new Thread()
{
public void run()
{
System.out.println("Do something before closing the frame!");
}
});
setVisible(true);
}

public static void main(String[] args)
{
new Test();
}
}

Answer 2

给你写个简单的例子吧。import java.awt.Dimension;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.JFrame;
public class Test extends JFrame implements WindowListener{
public Test(){
this.setSize(new Dimension(100,100));
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
this.addWindowListener(this);
}
@Override
public void windowActivated(WindowEvent e) {
}
@Override
public void windowClosed(WindowEvent e) {
System.out.println("asdf");
}
@Override
public void windowClosing(WindowEvent e) {
System.out.println("asdf");
}
@Override
public void windowDeactivated(WindowEvent e) {
}
public void windowDeiconified(WindowEvent e) {
}
@Override
public void windowIconified(WindowEvent e) {
}
@Override
public void windowOpened(WindowEvent e) {
}

public static void main(String[] arg){
new Test();
}
}

Answer 3

也就是说，当你点击X图片的时候，会触发WindowListener的关闭事件。你需要做一些事情，可以在这个事件中作。