draw.java

这是一个简单的图形用户程序

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
class MyOval
{
	private int X1;
	private int Y1;
	private int X2;
	private int Y2;
	public MyOval(int X1,int Y1,int X2,int Y2)
	{
		this.X1=X1;
		this.Y1=Y1;
		this.X2=X2;
		this.Y2=Y2;
	}
	public void drawMe(Graphics g)
	{
		g.drawOval(X1,Y1,X2,Y2);
	}
}
public class Draw extends Frame
{
	Vector vOval=new Vector();
	public static void main(String[] args)
	{
		Draw d=new Draw();
		d.init();
	}
	public void paint(Graphics g)
	{
		g.setColor(Color.red);
		Enumeration e=vOval.elements();
		while(e.hasMoreElements())
		{
			MyOval ml=(MyOval)e.nextElement();
			ml.drawMe(g);
		}
	}
	public void init()
	{
		this.addWindowListener(new WindowAdapter()
		{
			public void windowClosing(WindowEvent e)
			{
				((Window)e.getSource()).dispose();
				System.exit(0);
			}
		});
		addMouseListener(new MouseAdapter()
		  { 
		  	int orgX;
		  	int orgY;
			  public void mousePressed(MouseEvent e)
			  {
				   orgX=e.getX();
				   orgY=e.getY();
			  }
			  public void mouseReleased(MouseEvent e)
			  {
				   Graphics g=e.getComponent().getGraphics();
				   g.setColor(Color.red);
				   g.drawOval(orgX,orgY,e.getX(),e.getX());
				   g.fillOval(orgX,orgY,e.getX(),e.getX());
				   vOval.add(new MyOval(orgX,orgY,e.getX(),e.getY()));
			   }
		   });
		 this.setSize(400,350);
		 setVisible(true);
	}
}