用Java设计一个图形界面（GUI）的计算器应用程序，完成简单的算术运算

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五分钟搞定，先给你发个简单的，照例子自己去做你想要的计算器
package aaa;
import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class YunSuan implements ActionListener,ItemListener
{
public static JFrame jf;
public static Container c;
public static JTextField jtf1,jtf2,jtf3;
public static JButton jb1;
public static Choice c2;

public static String fuhao="";

public YunSuan()
{
jf=new JFrame("加减乘除运算");
c=jf.getContentPane();
c.setLayout(new FlowLayout());
jtf1=new JTextField(10);
jtf2=new JTextField(10);
jtf3=new JTextField(10);
c2=new Choice();
jb1=new JButton("=");

}

public void Jiemian()
{

c.add(jtf1);
c2.addItemListener(this);
c2.add("");
c2.add("+");
c2.add("-");
c2.add("*");
c2.add("/");
c.add(c2);
c.add(jtf2);
jb1.addActionListener(this);
c.add(jb1);
c.add(jtf3);

jf.setLocation(200,100);
jf.setVisible(true);
jf.pack();
}
public static void main(String args[])
{
YunSuan ys=new YunSuan();
ys.Jiemian();
}

public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
double s1=Integer.parseInt(jtf1.getText());
double s2=Integer.parseInt(jtf2.getText());
double result=0;
if(fuhao.equals("+"))
{
result=s1+s2;
String result2=String.valueOf(result);
jtf3.setText(result2);
}
if(fuhao.equals("-"))
{
result=s1-s2;
String result2=String.valueOf(result);
jtf3.setText(result2);
}
if(fuhao.equals("*"))
{
result=s1*s2;
String result2=String.valueOf(result);
jtf3.setText(result2);
}
if(fuhao.equals("/"))
{
result=s1/s2;
String result2=String.valueOf(result);
jtf3.setText(result2);
}
}

public void itemStateChanged(ItemEvent ie)
{
if(ie.getSource()==c2)
{
String str1=c2.getSelectedItem();
fanhui(str1);
}
}
public String fanhui(String str2)
{
return fuhao=str2;
}
}