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();
        }
    }
}