1 package ch11;
 2 
 3 import javax.swing.JFrame;
 4 
 5 public class MyfirstJframe {
 6         
 7     public static void main(String[] args) {
 8       JFrame f=new JFrame("我的窗口");
 9       f.setSize(300, 400);
10       f.setLocation(500, 500);
11       f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
12       f.setVisible(true);
13     }
14 
15 }

 1 package ch11;
 2 
 3 import java.awt.HeadlessException;
 4 
 5 import javax.swing.JFrame;
 6 
 7 public class MyfirstJframe_2 extends JFrame {
 8     
 9     public MyfirstJframe_2() throws HeadlessException {
10         super();
11         setTitle("我的窗口");
12         setSize(500, 500);
13         setLocation(400, 400);
14         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
15     }
16     
17     public static void main(String[] args) {
18         MyfirstJframe_2 f=new MyfirstJframe_2();
19         f.setVisible(true);
20     }
21 
22     
23 
24 }

 1 package ch11;
 2 import java.awt.*;
 3 import javax.swing.*;
 4 public class MyFirstJFrame_3 extends JFrame{
 5 
 6     private JLabel la;
 7     private JButton lb;
 8     
 9     public MyFirstJFrame_3() {
10         super();
11         setTitle("我的窗口");
12         setBounds(400, 400, 400, 400);
13         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
14         setLayout(new FlowLayout());
15         la=new JLabel("这是我设计的第一个窗口!");
16         Font ft=new Font("黑体",Font.ITALIC,25);
17         la.setFont(ft);
18         la.setForeground(Color.RED);
19         add(la);
20         lb=new JButton("点击该按钮,标签中显示字体将变小");//此时没反应
21         add(lb);
22         
23     }
24     public static void main(String[] args) {
25         MyFirstJFrame_3 f=new MyFirstJFrame_3();
26         f.setVisible(true);
27     }
28 
29 }

 1 package ch11;
 2 
 3 import java.awt.*;
 4 import java.awt.event.*;
 5 import javax.swing.*;
 6 
 7 public class MyFirstJFrame_4 extends JFrame implements ActionListener{
 8 
 9     private JLabel la;
10     private JButton lb;
11     
12     public MyFirstJFrame_4() throws HeadlessException {
13         super();
14         setTitle("我的窗口");
15         setSize(400, 400);
16         setLocation(400, 400);
17         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18         setLayout(new FlowLayout());
19         la= new JLabel("这是我设计的第一个窗口");
20         Font ft=new Font("宋体", Font.BOLD, 25);
21         la.setFont(ft);
22         la.setForeground(Color.blue);
23         add(la);
24         lb=new JButton("单点击该按钮,标签中显示字体变小");
25         add(lb);
26         lb.addActionListener(this);
27     }
28 
29     public static void main(String[] args) {
30         MyFirstJFrame_4 f=new MyFirstJFrame_4();
31         f.setVisible(true);
32 
33     }
34 
35     @Override
36     public void actionPerformed(ActionEvent e) {//重写单点击事件响应处理的方法
37         Font ft=new Font("宋体", Font.BOLD, 11);
38         la.setFont(ft);
39         lb.setEnabled(false);
40     }
41 
42 }