给面板添加背景图片

给JPanel添加背景图片:

代码入下:

package test;

import java.awt.Graphics;
import java.awt.Image;

import javax.swing.ImageIcon;
import javax.swing.JPanel;

public class BackgroundPanel extends JPanel {
    private int width;
    private int height;
    private Image img;
    
    public BackgroundPanel(String imgPath, int width, int height) {
        this(new ImageIcon(imgPath).getImage(), width, height);
    }
    
    public BackgroundPanel(Image img, int width, int height) {
        this.width = width;
        this.height = height;
        this.img = img;
    }
    
    public void paint(Graphics g) {
        g.drawImage(img, 0, 0, width, height, null);
    }
    
}

测试代码:

package test;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Test {
    public static void main(String[] args) {
        final int WIDTH = 600;
        final int HEIGHT = 600;
        JFrame frame = new JFrame("测试背景面板");
        JPanel panel = new BackgroundPanel("imgPath", WIDTH, HEIGHT);
        frame.add(panel);
        frame.setSize(WIDTH, HEIGHT);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}