滑轮代码

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class hualun extends Applet{
int y1=200,y2=300;
public void init(){
setVisible(true);
setSize(500,500);
this.setBackground(Color.BLACK);
addMouseMotionListener(new MouseMontionHandler());
}
public void paint(Graphics g){
if(g==null)g=getGraphics();
g.setColor(new Color(255,255,255));
g.fillRect(50,100,100,20);
g.drawLine(100,120,100,150);
g.drawOval(85,135,30,30);

g.drawLine(85,150,85,y1);
g.fillRect(70,y1,30,30);
g.drawLine(115,150,115,y2);
g.fillRect(100,y2,30,30);
}
class MouseMontionHandler extends MouseMotionAdapter{
public void mouseDragged(MouseEvent e){
int x=e.getX();int y =e.getY();
if(x>=70&&x<=100){
if(y>y1){
y2=y2-(y-y1);
if(y2>=165){y1=y;repaint();}
if(y2<165){y2=y2+(y-y1);repaint();}
}
if(y<=y1){
y2=y2+y1-y;
if(y>=165)y1=y;repaint();
if(y<165) {y2=y2-(y-y1);repaint();}
}
}
if(100<=x&&x<=130){
if(y>y2){
y1=y1-(y-y2);
if(y1>=165){y2=y;repaint();}
if(y1<165){y1=y1+y-y2;repaint();}
}
if(y<=y2){
y1=y1+y2-y;
if(y>=165)y2=y;repaint();
if(y<165){y1=y1-y2+y;repaint();}
}
}
}
}//end calss

}