文章关键字：|JAVA|屏幕抓图|远程|桌面控制|方法|捕获|类|程序|

主要使用的是java.util.Robot类来捕获屏幕,可以实现对屏幕一个矩形区域的捕获,通过这个类,我们也可以实现一个远程桌面控制的程序。

package com.qiu.util;

import java.io.*;

import java.net.*;

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

import java.awt.image.*;

import javax.imageio.*;

import java.io.*;

/**@Author Qiu_BaiChao

*一个简单的屏幕抓图

*

**/

public class ScreenCapture {

     //test main

     public static void main(String[] args) throws Exception{

          String userdir = System.getProperty("user.dir");

          File tempFile = new File("d:","temp.png");

          ScreenCapture capture = ScreenCapture.getInstance();

          capture.captureImage();

          JFrame frame = new JFrame();

          JPanel panel = new JPanel();

          panel.setLayout(new BorderLayout());

          JLabel imagebox = new JLabel();

          panel.add(BorderLayout.CENTER,imagebox);

          imagebox.setIcon(capture.getPickedIcon());

          capture.saveToFile(tempFile);

          capture.captureImage();

          imagebox.setIcon(capture.getPickedIcon());

          frame.setContentPane(panel);

          frame.setSize(400,300);

          frame.show();

          System.out.println("Over");

     }

     private ScreenCapture() {

          try{

               robot = new Robot();

          }

          catch(AWTException e) {

               System.err.println("Internal Error: " + e);

               e.printStackTrace();

          }

          JPanel cp = (JPanel)dialog.getContentPane();

          cp.setLayout(new BorderLayout());

          labFullScreenImage.addMouseListener(new MouseAdapter() {

               public void mouseReleased(MouseEvent evn) {

                    isFirstPoint = true;

                    pickedImage = fullScreenImage.getSubimage(recX,recY,recW,recH);

                    dialog.setVisible(false);

               }

          });

          labFullScreenImage.addMouseMotionListener(new MouseMotionAdapter() {

               public void mouseDragged(MouseEvent evn) {

                    if(isFirstPoint) {

                         x1 = evn.getX();

                         y1 = evn.getY();

                         isFirstPoint = false;

                    }

                    else {

                         x2 = evn.getX();

                         y2 = evn.getY();

                         int maxX = Math.max(x1,x2);

                         int maxY = Math.max(y1,y2);

                         int minX = Math.min(x1,x2);

                         int minY = Math.min(y1,y2);

                         recX = minX;

                         recY = minY;

                         recW = maxX-minX;

                         recH = maxY-minY;

                         labFullScreenImage.drawRectangle(recX,recY,recW,recH);

                    }

               }

               public void mouseMoved(MouseEvent e) {

                    labFullScreenImage.drawCross(e.getX(),e.getY());

               }

          });

          cp.add(BorderLayout.CENTER,labFullScreenImage);

          dialog.setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));

          dialog.setAlwaysOnTop(true);

          dialog.setMaximumSize(Toolkit.getDefaultToolkit().getScreenSize());

          dialog.setUndecorated(true);

          dialog.setSize(dialog.getMaximumSize());

          dialog.setModal(true);

     }

     //Singleton Pattern

     public static ScreenCapture getInstance() {

          return defaultCapturer;

     } [SPAN]

     /**捕捉全屏慕*/

     public Icon captureFullScreen() {

          fullScreenImage = robot.createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));

          ImageIcon icon = new ImageIcon(fullScreenImage);

          return icon;

     }

     /**捕捉屏幕的一个矫形区域

     */

     public void captureImage() {

          fullScreenImage = robot.createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));

          ImageIcon icon = new ImageIcon(fullScreenImage);

          labFullScreenImage.setIcon(icon);

          dialog.setVisible(true);

     }

     /**得到捕捉后的BufferedImage*/

     public BufferedImage getPickedImage() {

          return pickedImage;

     }

     /**得到捕捉后的Icon*/

     public ImageIcon getPickedIcon() {

          return new ImageIcon(getPickedImage());

     }

     /**储存为一个文件,为PNG格式

     *@deprecated

     *replaced by saveAsPNG(File file)

     **/

     @Deprecated

     public void saveToFile(File file) throws IOException{

          ImageIO.write(getPickedImage(),defaultImageFormater,file);

     }

     /**储存为一个文件,为PNG格式*/

     public void saveAsPNG(File file) throws IOException {

          ImageIO.write(getPickedImage(),"png",file);

     }

     /**储存为一个JPEG格式图像文件*/

     public void saveAsJPEG(File file) throws IOException {

          ImageIO.write(getPickedImage(),"JPEG",file);

     }

     /**写入一个OutputStream*/

     public void write(OutputStream out) throws IOException{

          ImageIO.write(getPickedImage(),defaultImageFormater,out);

     }

     //singleton design pattern

     private static ScreenCapture defaultCapturer = new ScreenCapture();

     private int x1,y1,x2,y2;

     private int recX,recY,recH,recW; //截取的图像

     private boolean isFirstPoint = true;

     private BackgroundImage labFullScreenImage = new BackgroundImage();

     private Robot robot;

     private BufferedImage fullScreenImage;

     private BufferedImage pickedImage;

     private String defaultImageFormater = "png";

     private JDialog dialog = new JDialog();

}

/**显示图片的Label*/

class BackgroundImage extends JLabel{

     public void paintComponent(Graphics g) {

          super.paintComponent(g);

          g.drawRect(x,y,w,h);

          String area = Integer.toString(w)+" * "+ Integer.toString(h);

          g.drawString(area,x+(int)w/2-15,y+(int)h/2);

          g.drawLine(lineX,0,lineX,getHeight());

          g.drawLine(0,lineY,getWidth(),lineY);

     }

     public void drawRectangle(int x,int y,int width,int height) {

          this.x = x;

          this.y = y;

          h = height;

          w = width;

          repaint();

     }

     public void drawCross(int x,int y) {

          lineX = x;

          lineY = y;

          repaint();

     }

     int lineX,lineY;

     int x,y,h,w;

}