载入图片的几种常用方法/*** <p>Title: PaintPanel</p>* <p>Description:此程序演示如何载入图片,并让其作为panel的背景</p>* <p>Copyright: Copyright (c) 2005</p>* <p>Company: gift2u</p>* @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);    }  }} 　 测试代码: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();  }}: 运行图: 来源： 网上

评论