Java中如何添加背景图片？

mport java.awt.*;
import javax.swing.*;class ImagePanel extends JPanel {
    private Image backgroundImage;
    ImagePanel() {
        // 从系统中加载图片
        backgroundImage = new ImageIcon("image address").getImage();
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);

        if (backgroundImage != null) {
            g.drawImage(backgroundImage, 0, 0, getWidth(), getHeight(), this);
        }
    }
}

package cn.gk.com;import javax.swing.JFrame;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import static cn.gk.com.SwingConsole.run;public class StudySystem extends JFrame { /**
* @param args
* by Gk
* 26.07.09
*/

Container c = this.getContentPane();
// private MyDialog dlg = new MyDialog();
private JMenu[] menu = {new JMenu("应用学习"), new JMenu("休闲娱乐"), new JMenu("测试检验"),
new JMenu("网站链接"),new JMenu("功能介绍")};
private JMenuItem[] items = {
new JMenuItem("英语学习"),new JMenuItem("飞行棋"),new JMenuItem("听力测试"),new JMenuItem("百度"),
new JMenuItem("简介"), new JMenuItem("关于")
};
private MyAbout about = new MyAbout(null);
private IntroFrame inf = new IntroFrame();
// JLabel lb = new JLabel("欢迎进入多媒体自主学习平台");
private ImageIcon imageicon;
private Image image;
public StudySystem() {
// c.setLayout(new BorderLayout());
// add(jp);

// GirdBagLayout layout = new GridBagLayout();
// setLayout(new BorderLayout());
// add(jp,BorderLayout.CENTER);
// setTitle("多媒体系统");
imageicon = new ImageIcon("summer.jpg");
JPanel jp = new JPanel() {
public void paintComponent(Graphics g){
super.paintComponent(g);
//ImageIcon imgIcon = new ImageIcon("summer.jpg");
image = imageicon.getImage();
g.drawImage(image,0,0,null);
}
};
add(jp);
Toolkit kit = Toolkit.getDefaultToolkit();//设置顶层容器为显示屏居中显示
Dimension screenSize = kit.getScreenSize();
int width = screenSize.width;
int height = screenSize.height;
int x = (width - 500) / 2;
int y = (height - 500) / 2;
setLocation(x,y);
menu[0].add(items[0]);menu[1].add(items[1]);
menu[2].add(items[2]);menu[3].add(items[3]);
menu[4].add(items[4]);menu[4].add(items[5]);
items[4].addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
inf.setVisible(true);
}
});
items[5].addActionListener(new GK());
JMenuBar mb = new JMenuBar();
for(JMenu jm : menu)
mb.add(jm);
mb.setOpaque(false);
setJMenuBar(mb);

}

class GK implements ActionListener {
public void actionPerformed(ActionEvent e) {
about.setVisible(true);
}
}

/* public void setBackGround() {
((JPanel)this.getContentPane()).setOpaque(false);
   ImageIcon img = new ImageIcon("LD.jpg");
   JLabel background = new JLabel(img);
   this.getLayeredPane().add(background, new Integer(Integer.MIN_VALUE));
   background.setBounds(0, 0, img.getIconWidth(), img.getIconHeight());
}*/

public static void main(String[] args) {
// TODO Auto-generated method stub
run(new StudySystem(),500,500);
// new StudySystem();
}}这是我的源码，MyAbout和IntroFrame是我自己写的两个类。可是图片就是加不进去，请高手指教。

可以用1楼的方法来画，也可以用一个大大的jlabel来作为背景（就是利用set imageicon的方法，为label来设置图片），只需要将label放在最下面就可以了

imageicon = new ImageIcon("summer.jpg");
这路径对么？

对啊，summer.jpg放在class的文件夹里啊，编译没有出错啊！

package qwe;
import java.awt.event.*;
import java.awt.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;import javax.swing.*;public class ZhuCe1 extends JFrame {
private JLabel la_top, la_name, la_IP, la_pwd, la_rpwd; private JTextField t_name, t_IP; private JPasswordField t_pwd1, t_pwd2; private JButton bt1, bt2;
JLabel lbBg;
// public void setBack(){
// ((JPanel) this.getContentPane()).setOpaque(false);
// ImageIcon img = new ImageIcon(this.getClass().getResource("3.jpg"));
// JLabel background = new JLabel(img);
// this.getLayeredPane().add(background, new Integer(Integer.MIN_VALUE));
// background.setBounds(0, 0, img.getIconWidth(), img.getIconHeight());
// }
// public static void setPositionLeft(JComponent left, JComponent dest,
int leftMargin, int width, int height) {
int x = left.getX() + left.getWidth() + leftMargin;
int y = left.getY();
dest.setBounds(x, y, width, height);
} public static void setPositionTop(JComponent top, JComponent dest,
int topMargin, int width, int height) {
int x = top.getX();
int y = top.getY() + top.getHeight() + topMargin;
dest.setBounds(x, y, width, height);
} private void setComponentPosition(JPanel p) {

int txtWidth = 200;
int txtHeight = 25;
int lbWidth = 100;
int lbHeight = 25;
int topMargin = 10;
int leftMargin = 20;

la_name.setHorizontalAlignment(SwingConstants.RIGHT);
la_name.setBounds(new Rectangle(10,10,lbWidth, lbHeight));

la_name.setHorizontalAlignment(SwingConstants.RIGHT);
setPositionLeft(la_name, t_name, leftMargin, txtWidth, txtHeight); la_IP.setHorizontalAlignment(SwingConstants.RIGHT);
setPositionTop(la_name, la_IP, topMargin, lbWidth, lbHeight);
setPositionLeft(la_IP, t_IP, leftMargin, txtWidth, txtHeight);

la_pwd.setHorizontalAlignment(SwingConstants.RIGHT);
setPositionTop(la_IP, la_pwd, topMargin, lbWidth, lbHeight);
setPositionLeft(la_pwd, t_pwd1, leftMargin, txtWidth, txtHeight);

la_rpwd.setHorizontalAlignment(SwingConstants.RIGHT);
setPositionTop(la_pwd, la_rpwd, topMargin, lbWidth, lbHeight);
setPositionLeft(la_rpwd, t_pwd2, leftMargin, txtWidth, txtHeight); p.add(la_name,null);
p.add(t_name, null);
p.add(la_IP, null);
p.add(t_IP, null);
p.add(la_pwd, null);
p.add(t_pwd1, null);
p.add(la_rpwd, null);
p.add(t_pwd2, null);
} public ZhuCe1() {

ImageIcon titleIcon = new ImageIcon(getClass().getResource("123.png"));
this.setIconImage(titleIcon.getImage());

setTitle("IM注册对话框");
setLayout(new BorderLayout());
Container c = getContentPane(); JPanel p = new JPanel(new FlowLayout(1));
JPanel pMain=new JPanel(); la_top = new JLabel("用户注册基本资料:");
la_name = new JLabel("昵称:");
la_IP = new JLabel("I P地址:");
la_pwd = new JLabel("用户密码:");
la_rpwd = new JLabel("确认密码:");
t_name = new JTextField(10);
t_IP = new JTextField(10);
t_pwd1 = new JPasswordField(10);
t_pwd2 = new JPasswordField(10);
bt1 = new JButton("确认注册");
bt2 = new JButton("取消注册");
p.add(bt1);
p.add(bt2);

pMain.setLayout(null);
setComponentPosition(pMain);
c.add(BorderLayout.NORTH, la_top);
c.add(BorderLayout.CENTER, pMain);
c.add(BorderLayout.SOUTH, p);

bt2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if (e.getActionCommand().equals("取消注册")) {
System.exit(0);
}
}
}); bt1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
String la_name;
String la_IP;
String la_pwd;
la_name=new String(t_name.getText());
if(la_name.equals("")){
JOptionPane.showMessageDialog(null, "用户名不能为空");
return;
}
la_IP=new String(t_IP.getText());
if(la_IP.equals("")){
JOptionPane.showMessageDialog(null, "IP不能为空");
return;
}
la_pwd=new String(t_pwd1.getPassword());
if(la_pwd.equals("")){
JOptionPane.showMessageDialog(null, "密码不能为空");
return;
}
char[] s1 = t_pwd1.getPassword();
char[] s2 = t_pwd2.getPassword(); if (String.valueOf(s1).equals(String.valueOf(s2))) {
JOptionPane.showMessageDialog(null, "恭喜您,注册成功!");
} else {
JOptionPane.showMessageDialog(null, "两次输入密码不一致,请重新输入!");
return;
}

try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.exit(0);
}
Connection con = null;
Statement s = null;
ResultSet rs=null; try {
con = DriverManager
.getConnection(
"jdbc:mysql://210.41.34.251?useUnicode=true&characterEncoding=EUC_CN",
"root", ""); s = con.createStatement();
s.executeUpdate("insert into user_im (pwd, alias,ip) values ('"
+ t_pwd1.getText().toString()
+ "', '"
+ t_name.getText()
+ "', '"
+ t_IP.getText() + "');");
System.out.println("sucessfully!");
rs=s.executeQuery("select user_id from user_im where ip = '"+ t_IP.getText()+"'");
int id=0;
while(rs.next()){
id = rs.getInt("user_id");
}
JOptionPane.showMessageDialog(null, "您的ID是：" + id);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
try {
rs.close();
} catch (Exception e) {
}
try {
s.close();
} catch (Exception e) {
}
try {
con.close();
} catch (Exception e) {
}
}

} });

// this.setBack();
setVisible(true);
setSize(400, 230);
validate();
setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
}

public static void main(String args[]) {
new ZhuCe1();
}
}

可以使用相对路径的！
JPanel jp = new JPanel(){
  public void paintComponent(Graphics g){
    super.paintComponent(g);
    ImageIcon image = new ImageIcon(this.getClass().getResource(
     "src\\...(你相对工程的那个路径)"));
    g.drawImage(image.getImage,0,0,null);
  }
};
这样就可以使用相对路径了~~

调试易

Java中如何添加背景图片？

解决方案 »