最近开始学习java，参考教科书写了一个简单的计算器程序，贴上来，以便有用的时候可以参考。

呵呵，哈哈！！！

import java.awt.Container;

import java.awt.FlowLayout;

import java.awt.GridLayout;

import java.awt.Point;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.ItemEvent;

import java.awt.event.ItemListener;

import java.text.DecimalFormat;

import javax.swing.*;

public class Calculator extends JFrame implements ActionListener, ItemListener {

private JButton buttons[];

private JButton btClear, btTransfer;

private JTextField resultArea;

private JPanel resultPanel, buttonsPanel, transferPanel;

int cmbIndex = 1;

private String string[] = { "7", "8", "9", "/", "6", "5", "4", "*", "3",

"2", "1", "-", "0", ".", "=", "+" };

private String s = "", shu1 = "", shu2 = "", shu3 = "";

private static int fo = 0;

JComboBox cmbox;

private boolean ff = true;

public Calculator() {

super("进制计算器");

Container container = getContentPane();

container.setLayout(new FlowLayout());

resultPanel = new JPanel();

resultArea = new JTextField(13);

resultPanel.add(resultArea);

btClear = new JButton("C");

resultPanel.add(btClear);

transferPanel = new JPanel();

cmbox = new JComboBox();

cmbox.addItem("10进制转换为2进制");

cmbox.addItem("10进制转换为8进制");

cmbox.addItem("10进制转换为16进制");

cmbox.addItem("2进制转换为8进制");

cmbox.addItem("2进制转换为10进制");

cmbox.addItem("2进制转换为16进制");

cmbox.addItem("8进制转换为2进制");

cmbox.addItem("8进制转换为10进制");

cmbox.addItem("8进制转换为16进制");

cmbox.addItem("16进制转换为2进制");

cmbox.addItem("16进制转换为8进制");

cmbox.addItem("16进制转换为10进制");

transferPanel.add(cmbox);

btTransfer = new JButton("转");

transferPanel.add(btTransfer);

buttonsPanel = new JPanel();

buttonsPanel.setLayout(new GridLayout(4, 4, 10, 10));

butto