javaz中背景图片的添加

这段程序演示了如何载入图片的几种常用方法,
并同时演示了如何让其作为JPanel的背景.

1:

package test.International.chinajavaworld;

import javax.swing.JFrame;
import java.net.URL;
import javax.swing.ImageIcon;
import java.awt.MediaTracker;
import java.awt.Image;
import java.net.MalformedURLException;
import java.awt.GridLayout;
import javax.swing.JDialog;
import java.io.File;

public class TestPaintPanel {
public static void main(String[] args) {
JFrame fr = new JFrame();
fr.setTitle("GIFT-PaintPanel-演示载入图片的方法");
String urlstr = "http://photo.sohu.com/20040823/Img221677764.jpg";
String filestr="D://a.jpg";
//如果是自己的机器上...un comment following......
// String urlstr="file:///D://a.jpg";
URL url = null;
try {
url = new URL(urlstr);
}
catch (MalformedURLException ex) {
}

ImageIcon icon = new ImageIcon(url);

//////////////////loadimage//////////////////////
Image image = fr.getToolkit().getImage(url);
MediaTracker tracker = new MediaTracker(fr);
tracker.addImage(image, 0);
try {
tracker.waitForID(0);
}
catch (InterruptedException ie) {}
////////////////////////////////////////////////
fr.getContentPane().setLayout(new GridLayout(2, 2));
fr.setSize(500, 600);

fr.getContentPane().add(new PaintPanel(image));
fr.getContentPane().add(new PaintPanel(urlstr));
fr.getContentPane().add(new PaintPanel(icon));
fr.getContentPane().add(new PaintPanel(url));
//this is a litter different...
JDialog dialog = new JDialog(fr, "GIFT-演示让图片成为背景", true);
//本机上的文件...
dialog.getContentPane().add(new PaintPanel(new File(filestr)));
dialog.setSize(200, 200);

fr.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
fr.setVisible(true);
dialog.setVisible(true);
fr.validate();
}

}

2:

package test.International.chinajavaworld;
/**
* Title: PaintPanel

* Description:此程序演示如何载入图片,并让其作为panel的背景

* Copyright: Copyright (c) 2005

* Company: gift2u

* @author liwu chinajavaworld
* @version 1.0
*/
import javax.swing.*;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.net.URL;
import java.net.*;

import java.awt.MediaTracker;
import java.io.File;
import javax.imageio.ImageIO;
import java.io.*;
import java.awt.Toolkit;

public class PaintPanel
extends JPanel {
Image image = null;

/**
* PaintPanel
* 外部给图片，直接载入
* @param image Image
*/
public PaintPanel(Image image) {
this.image = image;
}
/**
* PaintPanel
* 外部给出file引用,通过ImageIO载入
* @param file File
*/
public PaintPanel(File file) {
try {
Image readImage = ImageIO.read(file);
this.image = readImage;
}
catch (IOException ex) {
}
}

/**
* PaintPanel
*外部给出string路径，通过Toolkit载入
* @param string String
*/
public PaintPanel(String string) {
URL url = null;
try {
url = new URL(string);
}
catch (MalformedURLException ex) {
}
image = Toolkit.getDefaultToolkit().getImage(url);

MediaTracker tracker = new MediaTracker(this);
tracker.addImage(image, 0);
try {
tracker.waitForID(0);
}
catch (InterruptedException ie) {
}

}

/**
* PaintPanel
*外部给出ImageIcon，利用ImageIcon载入
* @param icon ImageIcon
*/
public PaintPanel(ImageIcon icon) {
this.image = icon.getImage();
}

/**
* PaintPanel
* 外部给出URL，利用ImageIcon载入
* @param icon url
*/
public PaintPanel(URL url) {
ImageIcon icon = new ImageIcon(url);
this.image = icon.getImage();
}

public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
if (image != null) {
g2d.drawImage(image, 0, 0, this);
}
}
}

一个简单的frame背景

import java.awt.*;
import java.awt.event.*;

public class TestImage {

public TestImage() {
}
Frame f;
public static void main(String args[]){
TestImage b=new TestImage();
b.go();
}
public void go() {
Frame f=new Frame();
Image im=f.getToolkit().getImage("F://Wallpaper//宽屏壁纸d.jpg");
f.setSize(585,300);
f.setVisible(true);
Graphics e=f.getGraphics();
f.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
);
while(f.getFocusableWindowState()){
e.drawImage(im,0,0,580,300,f);
}

}
}