java学习笔记_GUI(5)

 1 import javax.swing.*;
 2 import java.awt.event.*;
 3 import java.awt.*;
 4 
 5 class MyPanel_2 extends JPanel {
 6     public void paintComponent( Graphics g ) {
 7         g.fillRect(0, 0, this.getWidth(), this.getHeight());
 8         int red = (int) (Math.random() * 255);
 9         int green = (int) (Math.random() * 255);
10         int blue = (int) (Math.random() * 255);
11         Color randomColor = new Color(red, green, blue);
12         g.setColor(randomColor);
13         g.fillOval(70, 40, 100, 100);
14     }
15 }
16 
17 class Gui{
18     
19     JButton button = new JButton("change color");
20     JButton button_change_label = new JButton("change label");
21     JLabel label = new JLabel("I‘m a label");
22     JFrame frame = new JFrame();
23     
24     private void set_frame() {
25         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
26         frame.setSize(800, 600);
27         frame.setVisible(true);
28     }
29     
30     public void show_my_panel() {
31         set_frame();
32         frame.getContentPane().add(BorderLayout.SOUTH, button);
33         button.addActionListener(new ColorButtonActionListener());
34 
35         frame.getContentPane().add(BorderLayout.EAST, button_change_label);
36         button_change_label.addActionListener(new LabelButtonActionListener() );
37         
38         frame.getContentPane().add(BorderLayout.WEST, label);
39         
40         frame.getContentPane().add(BorderLayout.CENTER,new MyPanel_2());
41     }
42 
43     class ColorButtonActionListener implements ActionListener {
44         public void actionPerformed( ActionEvent event ) {
45             frame.repaint();
46         }
47     }
48 
49     class LabelButtonActionListener implements ActionListener {
50         public void actionPerformed( ActionEvent event ) {
51             label.setText("That hurt!");
52         }
53     }
54 }
55 
56 class GuiTest {
57     public static void main( String[] args ) {
58         Gui gui = new Gui();
59         gui.show_my_panel();
60     }
61 }