16.4

 1 import java.awt.*;
 2 import java.awt.event.ActionEvent;
 3 import java.awt.event.ActionListener;
 4 
 5 import javax.swing.*;
 6 import javax.swing.border.LineBorder;
 7 
 8 
 9 public class Test_16_4 extends JFrame{
10     JTextField JT1 = new JTextField(5);
11     JTextField JT2 = new JTextField(5);
12     JTextField JT3 = new JTextField(5);
13     JButton JB_add = new JButton("Add");
14     JButton JB_sub = new JButton("Subtract");
15     JButton JB_mul = new JButton("Multiply");
16     JButton JB_div = new JButton("Divide");
17     
18     public Test_16_4(){
19         JPanel JP1 = new JPanel();
20         JPanel JP2 = new JPanel();
21         
22         NewListener nl = new NewListener();
23         
24         setLayout(new FlowLayout());
25         JP1.add(new JLabel("Number 1"));
26         JP1.add(JT1);
27         JP1.add(new JLabel("Number 2"));
28         JP1.add(JT2);
29         JP1.add(new JLabel("Result"));
30         JP1.add(JT3);
31         JP1.setBorder(new LineBorder(Color.BLACK,1));
32         
33         setLayout(new FlowLayout());
34         JP2.add(JB_add);
35         JP2.add(JB_sub);
36         JP2.add(JB_mul);
37         JP2.add(JB_div);
38         JP2.setBorder(new LineBorder(Color.black,1));
39         
40         setLayout(new BorderLayout(0,5));
41         add(JP1,BorderLayout.CENTER);
42         add(JP2,BorderLayout.SOUTH);
43         
44         JB_add.addActionListener(nl);
45         JB_sub.addActionListener(nl);
46         JB_mul.addActionListener(nl);
47         JB_div.addActionListener(nl);
48     }
49     public static void main(String[] args) {
50         // TODO Auto-generated method stub
51         Test_16_4 T1 = new Test_16_4();
52         T1.pack();
53         T1.setTitle("Test_16_4");
54         T1.setLocationRelativeTo(null);
55         T1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
56         T1.setVisible(true);
57     }
58     
59     class NewListener implements ActionListener{
60         
61         @Override
62         public void actionPerformed(ActionEvent e) {
63             // TODO Auto-generated method stub
64             double number1 = Double.parseDouble(JT1.getText());
65             double number2 = Double.parseDouble(JT2.getText());
66             if(e.getSource() == JB_add){
67                 JT3.setText(number1+number2+"");
68             }else if(e.getSource() == JB_sub){
69                 JT3.setText(number1-number2+"");
70             }else if(e.getSource() == JB_mul){
71                 JT3.setText(number1*number2+"");                
72             }else if(e.getSource() == JB_div){
73                 JT3.setText(number1/number2+"");
74             }
75         }
76         
77     }
78 }
Test_16_4.java
效果图：