16.2

 1 import javax.swing.*;
 2 import java.awt.*;
 3 import java.awt.event.*;
 4
 5 public class Exercise16_2 extends JFrame
 6     implements ComponentListener {
 7   public Exercise16_2() {
 8     // Set the window title
 9     setTitle("Exercise16_2");
10
11     // Register the frame as a listener for component events
12     this.addComponentListener(this);
13   }
14
15   /** Main method */
16   public static void main(String[] args) {
17     Exercise16_2 frame = new Exercise16_2();
18     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
19     frame.setSize(100, 80);
20     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
21     frame.setLocationRelativeTo(null); // Center the frame
22     frame.setVisible(true);
23   }
24
25   public void componentMoved(ComponentEvent e) {
26     System.out.println("Component moved");
27   }
28
29   public void componentHidden(ComponentEvent e) {
30     System.out.println("Component hidden");
31   }
32
33   public void componentResized(ComponentEvent e) {
34     System.out.println("Component resized");
35   }
36
37   public void componentShown(ComponentEvent e) {
38     System.out.println("Component shown");
39   }
40 }

Exercise16_2.java

效果：