drawline.java

用java编写的一些初级代码

import java.awt.*;
import java.awt.event.*;
public class drawline extends Frame 
{
    int ox;
    int oy;
    int ex;
    int ey;
    Image ig=null;
    Graphics og=null;
    public static void main(String [] args)
    {
	drawline dl=new drawline();
	dl.init();
    }
    public void paint(Graphics g)
    {
	if(ig!=null)
	    g.drawImage(ig,0,0,this);
    }
    public void init()
    {
	setSize(200,200);
	setVisible(true);
	Dimension d =getSize();
	ig=createImage(d.width,d.height);
	og=ig.getGraphics();
	addMouseListener(new MouseAdapter()
		{
		    public void mousePressed(MouseEvent e)
	{
	    ox=e.getX();
	    oy=e.getY();
	}
		    public void mouseReleased(MouseEvent e)
	{
	    ex=e.getX();
	    ey=e.getY();
	    og.setColor(Color.red);
	    og.setFont(new Font("System",Font.ITALIC|Font.BOLD,12));
	    og.drawString(new String(ox+","+oy),ox,oy);
	    og.drawString(new String(ex+","+ey),ex,ey);
	    og.drawLine(ox,oy,ex,ey);
	    repaint();
	}
		});

    }
}