MILY: 宋体; mso-bidi-font-size: 13.5pt"> 

//画正弦曲线程序

import java.applet. *;
import java.awt.*;
import java.awt.event.*;
public class ko12_3 extends Applet implements ActionListener
{
int x,y;
double a;
Button bn1=new Button("Sin波形");
Button bn2=new Button("清除");
public void init()
{
add(bn1);
add(bn2);
bn1.addActionListener(this);
bn2.addActionListener(this);
}
public void actionPerformed(ActionEvent e)
{
Graphics g=getGraphics();
if(e.getSource()==bn1)
{
for(x=0;x<=360;x+=9)
{
a=Math.sin(x*Math. PI/180);
y=(int)(80+40*a);
g.drawString("*",x,y);
}
}
if(e.getSource()==bn2)
repaint();
}
}
//ko12_3.html
<APPLET CODE="ko12.3class"width=280 height=160>
</APPLET>