java学习笔记_GUI(3)

如何加入自己定义的Panel

 import javax.swing.*;
 import java.awt.event.*;
 import java.awt.*;

 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 }

 class Gui implements ActionListener{

     JButton button = new JButton("click me");
     JFrame frame = new JFrame();

     private void set_frame() {
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setSize(300, 200);
         frame.setVisible(true);
     }

     public void show_button() {
         set_frame();
         frame.getContentPane().add(button);
         button.addActionListener(this);
     }

     public void show_my_panel() {
         set_frame();
         frame.getContentPane().add(new MyPanel());
     }

     public void actionPerformed( ActionEvent event ) {
         button.setText("I've been clicked!");
     }
 }

 class GuiTest {
     public static void main( String[] args ) {
         Gui gui = new Gui();
         if ( args.length > 0 ) {
             gui.show_my_panel();
         }
         else {
             gui.show_button();
         }
     }
 }