作者：wflm
email: wflm@263.net
日期：6/22/2001 1:44:29 AM
捕獲當前屏幕圖像。
希望多多交流。8-）
package com.borland.samples.welcome;

/**
 * Title:
 * Description:
 * Copyright:    Copyright (c) 2001
 * Company:
 * @author
 * @version 1.0
 */
import java.awt.*;
import java.awt.image.*;
import com.sun.image.codec.jpeg.*;

class ImageCanvas extends Canvas{
  private Image image;
  private Dimension prefSize;

  public ImageCanvas(Image image){
    this.image = image;
    calculatePreferredSize();
  }

  public void setImage(Image image){
    this.image = image;
    calculatePreferredSize();
    repaint();
  }

  private void calculatePreferredSize(){
    prefSize = new Dimension(image.getWidth(this),image.getHeight(this));
    System.out.println(image.getWidth(this));
    setSize(prefSize);
  }
  public Dimension getPreferredSize() {
     return prefSize;
  }
  public Dimension getMinimumSize() {
     return prefSize;
  }
  public void update(Graphics g){
     paint(g);
  }
  public void paint(Graphics g){
     g.drawImage(image,0,0,null);
  }
}

class ImageUtils{
  public static Image getScreenImage(){
    Robot robot;
    try {
      robot = new Robot();
    }catch(Exception e) {
      throw new RuntimeException("unable to construct Robot");
    }
    Dimension screenDims =Toolkit.getDefaultToolkit().getScreenSize();
    Image screen =robot.createScreenCapture(new Rectangle(450,350,screenDims.width,screenDims.height)).getScaledInstance(400,300,Image.SCALE_SMOOTH);
    MediaTracker tracker =new MediaTracker(new Label());
    tracker.addImage(screen,1);
    try {
      tracker.waitForID(0);
    }catch(InterruptedException e) { /** ... */ }
    return screen;
  }
}

public class ScreenCapture extends Frame{
  private ImageCanvas canvas =new ImageCanvas(ImageUtils.getScreenImage());
  public ScreenCapture(){
    add(canvas);
    setSize(400,300);
    setVisible(true);
    Thread imageThread =new UpdateThread();
    imageThread.setDaemon(true);
    imageThread.start();
}
  class UpdateThread extends Thread{
   public void run(){
      while(true){
        try {
          Thread.currentThread().sleep(1000);
        }
        catch (Exception ex) {

        }
        canvas.setImage(ImageUtils.getScreenImage());
        validate();
     }
    }
  }

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

  }
}