canvastest.java

这是一个java程序

/*
 * 1.1 version.
 */

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

public class CanvasTest extends Frame
{

	public static void main(String args[])
	{
		CanvasTest fr = new CanvasTest("Image Canvas Test");
	    Dimension preferredImageSize = new Dimension(400, 400);

		Image image1 = Toolkit.getDefaultToolkit().getImage( "1.gif" );

        ImageCanvas ic1 = new ImageCanvas(image1, preferredImageSize);

		ScrollPane sp = new ScrollPane();
		sp.add(ic1); 

        fr.add(sp, "Center");

		fr.setSize(500, 500);
		fr.setVisible(true);
    }
	
	public CanvasTest(String str)
	{
		super(str);

		addWindowListener( new WindowAdapter()
			{
				public void windowClosing(WindowEvent e)
				{
                    System.exit(0);
				}
			}
		);
	}
}

class ImageCanvas extends Canvas
{
    Image image;
    Dimension preferredSize;

    ImageCanvas(Image img, Dimension prefSize) {
        image = img;
        preferredSize = prefSize;
    }

    public Dimension minimumSize() {
        return new Dimension(10, 10);
    }

    public Dimension preferredSize() {
        return preferredSize;
    }

    public void paint(Graphics g) {
        g.drawImage(image, 0, 0, getBackground(), this);
    }
}