java学习笔记_GUI(5)

demo如何为不同的button创建对应的响应函数

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

class MyPanel_2 extends JPanel {
    public void paintComponent( Graphics g ) {
        g.fillRect(0, 0, this.getWidth(), this.getHeight());
        int red = (int) (Math.random() * 255);
        int green = (int) (Math.random() * 255);
        int blue = (int) (Math.random() * 255);
        Color randomColor = new Color(red, green, blue);
        g.setColor(randomColor);
        g.fillOval(70, 40, 100, 100);
    }
}

class Gui{
    
    JButton button = new JButton("change color");
    JButton button_change_label = new JButton("change label");
    JLabel label = new JLabel("I'm a label");
    JFrame frame = new JFrame();
    
    private void set_frame() {
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(800, 600);
        frame.setVisible(true);
    }
    
    public void show_my_panel() {
        set_frame();
        frame.getContentPane().add(BorderLayout.SOUTH, button);
        button.addActionListener(new ColorButtonActionListener());

        frame.getContentPane().add(BorderLayout.EAST, button_change_label);
        button_change_label.addActionListener(new LabelButtonActionListener() );
        
        frame.getContentPane().add(BorderLayout.WEST, label);
        
        frame.getContentPane().add(BorderLayout.CENTER,new MyPanel_2());
    }

    class ColorButtonActionListener implements ActionListener {
        public void actionPerformed( ActionEvent event ) {
            frame.repaint();
        }
    }

    class LabelButtonActionListener implements ActionListener {
        public void actionPerformed( ActionEvent event ) {
            label.setText("That hurt!");
        }
    }
}

class GuiTest {
    public static void main( String[] args ) {
        Gui gui = new Gui();
        gui.show_my_panel();
    }
}