import java.awt.*;
import java.io.*;
import java.applet.*;
import java.awt.event.*;
import javax.swing.*;
public class Text extends Applet implements TextListener,ItemListener,ActionListener{
Checkbox one,two,three,four;
TextField a,b,c;
double x1,x2,sum;
public void init(){
CheckboxGroup num=new CheckboxGroup();
Checkbox one=new Checkbox("+",false,num);
Checkbox two=new Checkbox("-",false,num);
Checkbox three=new Checkbox("*",false,num);
Checkbox four=new Checkbox("/",false,num);
a=new TextField(5);
b=new TextField(5);
c=new TextField(5);
a.addTextListener(this);
b.addTextListener(this);
one.addItemListener(this);
two.addItemListener(this);
three.addItemListener(this);
four.addItemListener(this);
add(a);
add(b);
add(c);
add(one);
add(two);
add(three);
add(four);
}
public void itemStateChanged(ItemEvent ie){
if(one.getState()==true){sum=x1+x2;c.setText(String.valueOf(sum));
}
if(two.getState()==true){sum=x1-x2;c.setText(String.valueOf(sum));
}
if(three.getState()==true){sum=x1*x2;c.setText(String.valueOf(sum));
}
if(four.getState()==true){sum=x1/x2;c.setText(String.valueOf(sum));
}
}
public void textValueChanged(TextEvent te){
x1=Double.parseDouble(a.getText());
x2=Double.parseDouble(b.getText());
}
public void actionPerformed(ActionEvent ae){
}
}
一个只有+，-，*，/的小运用程序。但是无法调用“public void itemStateChanged(ItemEvent ie)”点击按扭没反映，请大家指点指点！！！谢谢！！！
------解决方案--------------------
怎么没有结帖啊