第六周作业——简单的图像缩放显示

import java.awt.Container;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import javax.swing.*;

public class ShowImgApp {
// static Image img1;
public static void main(String arg[]){
ImageFrame frame = new ImageFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
}
}

class ImageFrame extends JFrame{
public ImageFrame(){
setSize(WIDTH,HEIGHT);
setTitle("缩放显示图像");
//JPanel panel = new JPanel();
//this.add(panel);
ImagePanel panel = new ImagePanel();
Container contentPane =getContentPane();
contentPane.add(panel);
}
public static final int WIDTH=400;
public static final int HEIGHT=600;

class ImagePanel extends JPanel{
public ImagePanel(){
image = Toolkit.getDefaultToolkit().getImage("sinian.gif");
MediaTracker tracker = new MediaTracker(this);
tracker.addImage(image,1);
try {
tracker.waitForID(1);
}catch (InterruptedException exception){}
}
public void paintComponent(Graphics g){
super.paintComponent(g);
int w = image.getWidth(this);
int h = image.getHeight(this);
g.drawImage(image,5,10,null );
g.drawImage(image,150,40,w/2,h/2,this);
g.drawImage(image,10,200,w*2,h*2,this);
}
private Image image;
}

}