e1302.java

java小程序

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class E1302 extends JFrame
{
Container c;
JLabel label=new JLabel("鼠标绘图");//248页
private int x=-1,y=-1;
public E1302()
{
super("E1302.java:绘图测试");
c=getContentPane();
c.setLayout(new FlowLayout(FlowLayout.CENTER));
c.add(label);
addMouseMotionListener(new DragListener());
setSize(500,500);
setVisible(true);
}

class DragListener extends MouseMotionAdapter
{
public void mouseDragged(MouseEvent e)
{
x=e.getX();
y=e.getY();
repaint();
}
}

public void paint(Graphics g)
{
g.fillOval(x,y,3,3);
}
public static void main(String args[])
{
E1302 app=new E1302();
app.addWindowListener(new MyWindowListener());
}
}