Question

java中panel中设置背景图片

我编写一个登录窗口 有3个panel p1,p2,p3 分别需要不同的背景图片，应该怎么编写代码？请高手赐教

Answer 1

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

/*
* NewJFrame.java
*
* Created on 2010-4-25, 16:12:38
*/

package test;

import java.awt.*;
import javax.swing.*;
/**
*
* @author Administrator
*/
public class NewJFrame extends javax.swing.JFrame {
JScrollPane scrollPane;
ImageIcon icon;
Image image;

/** Creates new form NewJFrame */
public NewJFrame() {
initComponents();
icon = new ImageIcon("login1.jpg");
jPanel1.setPreferredSize( new Dimension(614, 363) );
scrollPane = new JScrollPane( jPanel1 );
getContentPane().add( jPanel1 );
}

/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
private void initComponents() {

jPanel1 = new javax.swing.JPanel()
{
protected void paintComponent(Graphics g)
{
g.drawImage(icon.getImage(), 0, 0, null);
super.paintComponent(g);
}
};
jPanel2 = new javax.swing.JPanel();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setResizable(false);

jPanel1.setOpaque(false);

jPanel2.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(0, 0, 0), 1, true));

javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 308, Short.MAX_VALUE)
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 140, Short.MAX_VALUE)
);

javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(149, 149, 149)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(154, Short.MAX_VALUE))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(161, 161, 161)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(62, Short.MAX_VALUE))
);

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);

pack();
}// </editor-fold>//GEN-END:initComponents

/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new NewJFrame().setVisible(true);
new NewJFrame().setSize(613, 365);
}
});
}

// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel jPanel2;
// End of variables declaration//GEN-END:variables

}