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写一个ImageJPanel类继承自JPanel,在paintComponent方法中用g.drawImage绘制32313133353236313431303231363533e4b893e5b19e31333337393539Image背景图片就挡不着第一张卡片上的四个按钮了。
完整的程序如下：(注意把背景图片的路径换成你的背景图片路径)import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSplitPane;
public class D extends JFrame implements ActionListener{
private static final long serialVersionUID = 1L;
JPanel jp1=new JPanel();
JPanel tmpjp1=new JPanel();
JPanel jp2=new JPanel();
JPanel card_jp1=new JPanel();
JPanel card_jp2=new JPanel();
JPanel card_jp3=new JPanel();
JPanel card_jp4=new JPanel();
JButton jb1=new JButton("按钮1");
JButton jb2=new JButton("按钮2");
JButton jb3=new JButton("按钮3");
JButton jb4=new JButton("按钮4");
JSplitPane jsp=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,jp1,jp2);
CardLayout cl=new CardLayout();
int j=1;
D(){
tmpjp1.setLayout(new GridLayout(4,1,5,5));
tmpjp1.add(jb1);tmpjp1.add(jb2);tmpjp1.add(jb3);tmpjp1.add(jb4);
jp1.add(tmpjp1);
jp2.setLayout(cl);
JPanel p[] = new JPanel[4];
p[0]=new ImageJPanel();
jp2.add(p[0],String.valueOf(0));
for(int i = 1; i 
p[i] = new JPanel();
jp2.add(p[i],String.valueOf(i));
}
JButton b[] = new JButton[4];
for(int i = 1; i 
int a = i + 1;
b[i] = new JButton("第" + a + "页,下一页");
b[i].addActionListener(this);
p[i].add(b[i]);
}
jsp.setResizeWeight(0.3);
add(jsp);
setSize(800,500);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
public static void main(String[] args) {
new D();
}
@Override
public void actionPerformed(ActionEvent e) {
cl.show(jp2,String.valueOf(j++));
if(j==4) j=0;
}
class ImageJPanel extends JPanel {
private Image image;
JButton card_jb1=new JButton("按钮1");
JButton card_jb2=new JButton("按钮2");
JButton card_jb3=new JButton("按钮3");
JButton jb = new JButton("第1页,下一页");
public ImageJPanel() {
super();
setOpaque(true);
add(card_jb1);
add(card_jb2);
add(card_jb3);
jb.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
cl.show(jp2,String.valueOf(j++));
if(j==4) j=0;
}
});
add(jb);
image = Toolkit.getDefaultToolkit().getImage( "C:/tmp/F/3.jpg");//这里换成你的背景图片地址
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
setBackground(Color.WHITE);
if (image != null) {
int height = image.getHeight(this);
int width = image.getWidth(this);
if (height != -1 && height > getHeight())
height = getHeight();
if (width != -1 && width > getWidth())
width = getWidth();
int x = (int) (((double) (getWidth() - width)) / 2.0);
int y = (int) (((double) (getHeight() - height)) / 2.0);
g.drawImage(image, x, y, width, height, this);
}
}
}
}

1.创建一个类ImagePanel,代码如下
import java.awt.BorderLayout;
import javax.swing.JPanel;
import java.io.File;
import javax.imageio.ImageIO;
import java.io.IOException;
import java.awt.Image;
import java.awt.Graphics;
import java.awt.Graphics2D;
class ImagePanel extends JPanel {
public ImagePanel() {
try {
File f = new File("Img/Login.gif");
img = ImageIO.read(f);
} catch (IOException e) {
e.printStackTrace();
}
}
private Image img;
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
if (img != null) {
g2.drawImage(img, 0, 0, getWidth(), getHeight(),
0, 0, img.getWidth(null), img.getHeight(null), null);
}
}
}
在新建的JPanel面板中调用:
把public class Welcome
extends JPanel
改为public class Welcome
extends ImagePanel
即可实现背景.
在对话框中使用如下:
public class Login
extends JDialog {
String pass;
static String name;
ImagePanel panel1 = new ImagePanel();  //使用ImagePanel类载入的背景替换默认Jpanel1做为背景

一起学习
1.创建一个类ImagePanel,代码如下
import java.awt.BorderLayout;
import javax.swing.JPanel;
import java.io.File;
import javax.imageio.ImageIO;
import java.io.IOException;
import java.awt.Image;
import java.awt.Graphics;
import java.awt.Graphics2D;
class ImagePanel extends JPanel {
public ImagePanel() {
try {
File f = new File("Img/Login.gif");
img = ImageIO.read(f);
} catch (IOException e) {
e.printStackTrace();
}
}
private Image img;
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
if (img != null) {
g2.drawImage(img, 0, 0, getWidth(), getHeight(),
0, 0, img.getWidth(null), img.getHeight(null), null);
}
}
}
在新建的JPanel面板中调用:
把public class Welcome
extends JPanel
改为public class Welcome
extendsImagePanel
即可实现背景.
在对话框中使用如下:
public class Login
extends JDialog {
String pass;
static String name;
ImagePanel panel1 = new ImagePanel();  //使用ImagePanel类载入的背景替换默认Jpanel1做为背景
下载本文示例代码
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设置jPanel的背景图片并且不影响jpanel的功能，可以正常向其中添加其他组件。
package login;

import java.awt.*;

import javax.swing.ImageIcon;
import javax.swing.JPanel;  
  
/** 
 * 有背景图片的Panel类 
 */  
public class BackgroundPanel extends JPanel {  
      
    /** 
     *  
     */  
    private static final long serialVersionUID = -6352788025440244338L;  
      
    private Image image = (Image) new ImageIcon("./Image/background.jpg").getImage();  
  
    // 固定背景图片，允许这个JPanel可以在图片上添加其他组件  
    protected void paintComponent(Graphics g) {  
        g.drawImage(image, 0, 0, this.getWidth(), this.getHeight(), this);  
    }  
}