java 背景颜色更改

简介

java 事件处理机制

code

/*
 * @Author: your name
 * @Date: 2020-10-28 22:38:26
 * @LastEditTime: 2020-10-29 10:01:15
 * @LastEditors: Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: /java/ImageTest.java
 */
import java.awt.*;

import javax.swing.*;

public class ImageTest {
    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            JFrame frame = new ButtonFrame();
            frame.setTitle("ImageTest");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setVisible(true);
        });
        ;
    }
}

/*
 * @Author: your name
 * @Date: 2020-10-29 09:41:06
 * @LastEditTime: 2020-10-29 10:01:27
 * @LastEditors: Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: /java/ButtonFrame.java
 */
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ButtonFrame extends JFrame {
    private JPanel buttonPanel;
    private static final int DEFAULT_WIDTH = 300;
    private static final int DEFAULT_HEIGHT = 200;

    public ButtonFrame() {

        setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

        // create button
        JButton yellowButton = new JButton("Yellow");
        JButton blueButton = new JButton("Blue");
        JButton redButton = new JButton("Red");

        buttonPanel = new JPanel();

        // add buttons to panel
        buttonPanel.add(yellowButton);
        buttonPanel.add(blueButton);
        buttonPanel.add(redButton);

        add(buttonPanel);

        // create button actions
        ColorAction yellowAction = new ColorAction(Color.YELLOW);
        ColorAction blueAction = new ColorAction(Color.BLUE);
        ColorAction redAction = new ColorAction(Color.RED);

        // associate actions with buttons
        yellowButton.addActionListener(yellowAction);
        blueButton.addActionListener(blueAction);
        redButton.addActionListener(redAction);
    }

    private class ColorAction implements ActionListener {
        private Color backgroundColor;

        public ColorAction(Color c) {
            backgroundColor = c;
        }

        public void actionPerformed(ActionEvent event) {
            buttonPanel.setBackground(backgroundColor);
        }
    }
}

image