Java GUI之事件監聽與處理

事件監聽和處理的根本技術，是回調。甲方提供接口，乙方實現接口並調用相應方法。

1. package com.sinosuperman.driver;
3. import java.awt.Dimension;
4. import java.awt.FlowLayout;
5. import java.awt.Toolkit;
6. import java.awt.event.ActionEvent;
7. import java.awt.event.ActionListener;
9. import javax.swing.JButton;
10. import javax.swing.JFrame;
11. import javax.swing.JOptionPane;
12. import javax.swing.JPanel;
14. public class MainBench {
15. public static void main(String[] args) {
16. JFrame frame = new MyFrame();
17. }
18. }
20. class MyFrame extends JFrame {
21. private static final long serialVersionUID = 1L;
22. Toolkit tk = Toolkit.getDefaultToolkit();
23. Dimension d = tk.getScreenSize();
24. JPanel panel;
25. public MyFrame() {
26. panel = new MyPanel();
27. this.add(panel);
28. this.setSize((int) d.getWidth() / 2, (int) d.getHeight() / 2);
29. this.setLocation((int) (d.getWidth() - this.getWidth()) / 2, (int) (d.getHeight() - this.getHeight()) / 2);
30. this.setResizable(false);
31. this.setVisible(true);
32. }
33. }
35. class MyPanel extends JPanel implements ActionListener {
36. private static final long serialVersionUID = 5263963243638550398L;
37. JButton okBtn;
38. JButton exitBtn;
39. public MyPanel() {
40. this.setLayout(new FlowLayout(FlowLayout.CENTER));
41. okBtn = new JButton("OK");
42. exitBtn = new JButton("Exit");
43. okBtn.addActionListener(this);
44. exitBtn.addActionListener(this);
45. this.add(okBtn);
46. this.add(exitBtn);
47. }
48. public void actionPerformed(ActionEvent e) {
49. Object source = e.getSource();
50. if (source == okBtn) {
51. JOptionPane.showMessageDialog(null, "You click the OK Button.");
52. } else {
53. JOptionPane.showMessageDialog(null, "You click the Exit Button.");
54. System.exit(0);
55. }
56. }
57. }