sup_7_1.java

各种关于JAVA的初级编程

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

public class sup_7_1
{
    public static void main(String args[])
    {
        new MoveBallFrame();
    }
}

class MoveBallFrame extends Frame implements AdjustmentListener
{
    Scrollbar myScrollbar = null;
    Point center = null;
    final int RADIUS = 10;
    
    MoveBallFrame()
    {
        super("我的窗口");
        center = new Point(100,100);
        myScrollbar = new Scrollbar(Scrollbar.VERTICAL,
            (int)center.getY(),5,0,(int)center.getY()*2);
        add("East", myScrollbar);
        myScrollbar.addAdjustmentListener(this);
        addWindowListener(new winClose());
        setSize(300,200);
        setVisible(true);
    }
    
    public void adjustmentValueChanged(AdjustmentEvent ce)
    {
        if(ce.getSource() == myScrollbar)
        {
            center.setLocation(center.getX(),ce.getValue());
            repaint();
        }
    }
    
    public void paint(Graphics g)
    {
        g.fillOval((int)center.getX()-RADIUS,(int)center.getY()-RADIUS,
            RADIUS,RADIUS);
    }
}

class winClose extends WindowAdapter
{
    public void windowClosing(WindowEvent we)
    {
        we.getWindow().dispose();
        System.exit(0);
    }
}