java学习笔记_GUI(3)

             1
            import javax.swing.*;
 2import java.awt.event.*;
 3import java.awt.*;
 4 5 class MyPanel extends JPanel {
 6     public void paintComponent( Graphics g ) {
 7         g.setColor( Color.orange );
 8         g.fillRect(20, 50, 100, 100);
 9     }
10 }
111213class Gui implements ActionListener{
1415     JButton button = new JButton("click me");
16     JFrame frame = new JFrame();
1718privatevoid set_frame() {
19        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
20         frame.setSize(300, 200);
21         frame.setVisible(true);
22    }
2324publicvoid show_button() {
25        set_frame();
26        frame.getContentPane().add(button);
27         button.addActionListener(this);
28    }
2930publicvoid show_my_panel() {
31        set_frame();
32frame.getContentPane().add(new MyPanel());
33    }
3435publicvoid actionPerformed( ActionEvent event ) {
36         button.setText("I‘ve been clicked!");
37    }
38}
3940class GuiTest {
41publicstaticvoid main( String[] args ) {
42         Gui gui = new Gui();
43if ( args.length > 0 ) {
44            gui.show_my_panel();
45        }
46else {
47            gui.show_button();
48        }
49    }
50 }