本文目录
- 怎么用java编写一个简单的计算器
- JAVA 编写计算器 要代码最简单的
- 用JAVA编写一个计算器
- 、使用JAVA语言编写一个简易的计算器
- 用JAVA编写一个简单的计算器，要求如下:
- 如何用java编写一个简单的计算器，只要能进行最基本的加减乘除运算就可以了，本人急用，简单易懂即可，大
- 用java编写简易计算器
- 用java编写简单计算器
- JAVA编写简单的计算器
- 怎么用JAVA编程编写一个计算器
怎么用java编写一个简单的计算器
/*
* @(#)JCalculator.java 1.00 06/17/2015
*/
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/**
* A simple calculator program.
* 《p》I saw this program in a QQ group, and help a friend correct it.《/p》
*
* @author Singyuen Yip
* @version 1.00 12/29/2009
* @see JFrame
* @see ActionListener
*/
public class JCalculator extends JFrame implements ActionListener {
/**
* Serial Version UID
*/
private static final long serialVersionUID = -169068472193786457L;
/**
* This class help close the Window.
* @author Singyuen Yip
*
*/
private class WindowCloser extends WindowAdapter {
public void windowClosing(WindowEvent we) {
System.exit(0);
}
}
int i;
// Strings for Digit & Operator buttons.
private final String str = { “7“, “8“, “9“, “/“, “4“, “5“, “6“, “*“,“1“,
“2“, “3“, “-“, “.“, “0“, “=“, “+“ };
// Build buttons.
JButton buttons = new JButton[str.length];
// For cancel or reset.
JButton reset = new JButton(“CE“);
// Build the text field to show the result.
JTextField display = new JTextField(“0“);
/**
* Constructor without parameters.
*/
public JCalculator() {
super(“Calculator“);
// Add a panel.
JPanel panel1 = new JPanel(new GridLayout(4, 4));
// panel1.setLayout(new GridLayout(4,4));
for (i = 0; i 《 str.length; i++) {
buttons[i] = new JButton(str[i]);
panel1.add(buttons[i]);
}
JPanel panel2 = new JPanel(new BorderLayout());
// panel2.setLayout(new BorderLayout());
panel2.add(“Center“, display);
panel2.add(“East“, reset);
// JPanel panel3 = new Panel();
getContentPane().setLayout(new BorderLayout());
getContentPane().add(“North“, panel2);
getContentPane().add(“Center“, panel1);
// Add action listener for each digit & operator button.
for (i = 0; i 《 str.length; i++)
buttons[i].addActionListener(this);
// Add listener for “reset“ button.
reset.addActionListener(this);
// Add listener for “display“ button.
display.addActionListener(this);
// The “close“ button “X“.
addWindowListener(new WindowCloser());
// Initialize the window size.
setSize(800, 800);
// Show the window.
// show(); Using show() while JDK version is below 1.5.
setVisible(true);
// Fit the certain size.
pack();
}
public void actionPerformed(ActionEvent e) {
Object target = e.getSource();
String label = e.getActionCommand();
if (target == reset)
handleReset();
else if (“0123456789.“.indexOf(label) 》 0)
handleNumber(label);
else
handleOperator(label);
}
// Is the first digit pressed?
boolean isFirstDigit = true;
/**
* Number handling.
* @param key the key of the button.
*/
public void handleNumber(String key) {
if (isFirstDigit)
display.setText(key);
else if ((key.equals(“.“)) && (display.getText().indexOf(“.“) 《 0))
display.setText(display.getText() + “.“);
else if (!key.equals(“.“))
display.setText(display.getText() + key);
isFirstDigit = false;
}
/**
* Reset the calculator.
*/
public void handleReset() {
display.setText(“0“);
isFirstDigit = true;
operator = “=“;
}
double number = 0.0;
String operator = “=“;
/**
* Handling the operation.
* @param key pressed operator’s key.
*/
public void handleOperator(String key) {
if (operator.equals(“+“))
number += Double.valueOf(display.getText());
else if (operator.equals(“-“))
number -= Double.valueOf(display.getText());
else if (operator.equals(“*“))
number *= Double.valueOf(display.getText());
else if (operator.equals(“/“))
number /= Double.valueOf(display.getText());
else if (operator.equals(“=“))
number = Double.valueOf(display.getText());
display.setText(String.valueOf(number));
operator = key;
isFirstDigit = true;
}
public static void main(String args) {
new JCalculator();
}
}
运行界面：
JAVA 编写计算器 要代码最简单的
学java的时候自己编的，很简单，能够连续输入计算式后进行计算
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.NumberFormat;
import java.util.ArrayList;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
/**简易计算器，能够进行简单的计算
*
* @see 2008.12.9
*/
public class CalculatorA
implements ActionListener{
private JFrame frame;
private JTextField field;
private JButton allButtons;
private JButton clearButton;
// private JButton backButton;
String result=““;//保存结果
StringBuilder sb = new StringBuilder();//保存要进行的计算式
int x = 0; //用来判断上一次的事件类型
String str = “123+456-789*0.=/“;
ArrayList《String》 arrayList = new ArrayList《String》();//保存计算式，通过方法进行运算
public CalculatorA(){
frame = new JFrame(“我的计算器v1.1“);
frame.setLocation(300,300);
field = new JTextField(25);
allButtons = new JButton;
for(int i=0;i《allButtons.length;i++){
allButtons[i]= new JButton(str.substring(i,i+1));
}
clearButton = new JButton(“CLEAR“);
// backButton = new JButton(“《——“);
init();
setFondAndColor();
addEventHander();
}
public void init(){
frame.setLayout(new BorderLayout());
JPanel northPanel = new JPanel();
JPanel centerPanel = new JPanel();
JPanel southPanel = new JPanel();
northPanel.setLayout(new FlowLayout());
centerPanel.setLayout(new GridLayout(4,4));
southPanel.setLayout(new FlowLayout());
northPanel.add(field);
for(int i=0;i《allButtons.length;i++){
centerPanel.add(allButtons[i]);
}
southPanel.add(clearButton);
//southPanel.add(backButton);
frame.add(northPanel,BorderLayout.NORTH);
frame.add(centerPanel,BorderLayout.CENTER);
frame.add(southPanel,BorderLayout.SOUTH);
}
//设置输入字体
public void setFondAndColor(){
field.setFont(new Font(“宋体“,Font.BOLD,24));
field.setBackground(new Color(100,200,200));
field.setForeground(Color.RED);
//设置字体从右起始
field.setHorizontalAlignment(JTextField.RIGHT);
}
public void showMi(){
frame.pack();
frame.setResizable(false);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void addEventHander(){
for(int i=0;i《allButtons.length;i++){
allButtons[i].addActionListener(this);
}
clearButton.addActionListener(this);
// backButton.addActionListener(this);
}
@Override
public void actionPerformed(ActionEvent e) {
String str = e.getActionCommand();//取得当前事件返回的值
if(“0123456789.“.indexOf(str)!=-1){
if(x == 0){ //当x为0时表示还没有进行输入
result=str;
sb.append(str);
field.setText(str);
x = 1;
}
else if(x == 1){
result = result +str;
sb.append(str);
field.setText(result);
x = 1;
}
else if(x == 2){
sb.delete(0,sb.length());
result = result+str;
sb.append(str);
field.setText(result);
x = 1;
}
else if(x == 3){
result = str;
sb.delete(0,sb.length());
arrayList.clear();
field.setText(str);
sb.append(str);
field.setText(str);
x = 1;
}
else if(x == 4){
result =““;
sb.delete(0,sb.length());
arrayList.clear();
result = str;
sb.append(str);
field.setText(str);
x = 1;
}
else{
result = result +str;
sb.append(str);
field.setText(result);
x = 1;
}
}
else if(“+*-/“.indexOf(str)!=-1){
if(x == 0){
field.setText(““);
x = 2;
}
else if(x == 1){
result = result + str;
arrayList.add(sb.toString());
arrayList.add(str);
sb.append(str);
field.setText(result);
x = 2;
}
else if(x == 2){
x = 2;
}
else if(x == 3){
field.setText(result+str);
arrayList.add(result);
arrayList.add(str);
result = result+str;
x = 2;
}
else if(x == 4){
result =““;
sb.delete(0,sb.length());
arrayList.clear();
x = 2;
}
else{
field.setText(result+str);
arrayList.add(result);
arrayList.add(str);
result = result+str;
x = 2;
}
}
else if(“=“.equals(str)){
if(x == 0){
field.setText(“0“);
arrayList.clear();
result = “0“;
x = 3;
}
else if(x == 1){
try{
arrayList.add(sb.toString());
arrayList = getResult(arrayList);
result = arrayList.get(0);
field.setText(result);
arrayList.clear();
x = 3;
}catch(Exception e1){
field.setText(“数据格式异常“);
x = 0;
}
}
else if(x == 2){
field.setText(“数据格式错误.....“);
arrayList.clear();
x = 0;
}
else if(x == 3){
field.setText(result);
x = 3;
}
else if(x == 4){
result =““;
sb.delete(0,sb.length());
arrayList.clear();
x = 3;
}
else {
try{
arrayList.add(sb.toString());
arrayList = getResult(arrayList);
result = arrayList.get(0);
field.setText(result);
arrayList.clear();
x = 3;
}catch(Exception e1){
field.setText(“数据格式异常“);
x = 0;
}
}
}
else if(“CLEAR“.equals(str)){
arrayList.clear();
field.setText(“0“);
arrayList.add(“0“);
x = 4;
}
else{
if(result.length()》1){
result = result.substring(0,result.length()-1);
if(sb.length()》0){
sb.delete(sb.length()-1,sb.length());
}
else {
sb.delete(0,1);
}
field.setText(result);
x = 5;
}
else{
result = ““;
sb.delete(0,sb.length());
arrayList.clear();
field.setText(“0“);
x = 0;
}
}
}
public static ArrayList《String》 getResult(ArrayList《String》 list){
String res = null;
String s = {“/“,“*“,“-“,“+“};
int i=0;
if(list.size()》1){
for(;i《s.length;){
if(s[i].equals(“/“)){
for(int j=0;j《list.size();j++){
if(list.get(j).equals(s[i])){
res = Double.toString(Double.parseDouble(list.get(j-1))/Double.parseDouble(list.get(j+1)));
//本地的数据格式
NumberFormat nf = NumberFormat.getInstance();
res = nf.format(Double.parseDouble(res));
res = getChange(res);
list.set(j-1,res);
list.remove(j);
list.remove(j);
getResult(list);
}
}
i++;
}
else if(s[i].equals(“*“)){
for(int j=0;j《list.size();j++){
if(list.get(j).equals(s[i])){
res = Double.toString(Double.parseDouble(list.get(j-1))*Double.parseDouble(list.get(j+1)));
NumberFormat nf = NumberFormat.getInstance();
res = nf.format(Double.parseDouble(res));
res = getChange(res);
list.set(j-1,res);
list.remove(j);
list.remove(j);
getResult(list);
}
}
i++;
}
else if(s[i].equals(“-“)){
for(int j=0;j《list.size();j++){
if(list.get(j).equals(s[i])){
res = Double.toString(Double.parseDouble(list.get(j-1))-Double.parseDouble(list.get(j+1)));
NumberFormat nf = NumberFormat.getNumberInstance();
res = nf.format(Double.parseDouble(res));
res = getChange(res);
list.set(j-1,res);
list.remove(j);
list.remove(j);
getResult(list);
}
}
i++;
}
else {
for(int j=0;j《list.size();j++){
if(list.get(j).equals(s[i])){
res = Double.toString(Double.parseDouble(list.get(j-1))+Double.parseDouble(list.get(j+1)));
NumberFormat nf = NumberFormat.getInstance();
res = nf.format(Double.parseDouble(res));
res = getChange(res);
list.set(j-1,res);
list.remove(j);
list.remove(j);
getResult(list);
}
}
i++;
}
}
}
return list;
}
//对数字字符串进行排除不必要符号
public static String getChange(String res){
String s_temp = ““;
char c = new char[res.length()];
for(int k=0;k《c.length;k++){
c[k] = res.charAt(k);
}
for(int k=0;k《c.length;k++){
if((c[k]》= ’0’ && c[k]《= ’9’)|| c[k] == ’.’){
s_temp += c[k];
}
}
return s_temp;
}
public static void main(String args){
new CalculatorA().showMi();
}
}
用JAVA编写一个计算器
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
public class Jisuanqi extends JFrame implements ActionListener {
/**
*
*/
private static final long serialVersionUID = 1L;
Result result = new Result(); // 定义text的面板
Number_Key number_key = new Number_Key(); // 定义按钮面板
// 当点击按钮+、-、*、/时，com = true
boolean com = false;
// 当i=0时说明是我们第一次输入，字符串text不会累加
int i = 0;
// 存放text的内容
String text = ““;
// 存放点击按钮+、-、*、/之前的数值
double defbutton = 0;
// +、-、*、/的代号分别为1，2，3，4
int symbol = 0;
// 构造函数
Jisuanqi() {
super(“WangJiao“); // 设定标题
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设定关闭窗体时退出程序
JPanel pane = new JPanel(); // 定义主面板
pane.setLayout(new BorderLayout());
setBounds(380, 220, 30, 80); // 前两个参数是在屏幕上显示的坐标，后两个是大小
// 替换图标
ImageIcon icon = new ImageIcon(“F:1.GIF“);
// Jisuanqi.class.getResource(“APPLE.GIF“)
// );
setIconImage(icon.getImage());
pane.add(result, BorderLayout.NORTH);
pane.add(number_key, BorderLayout.CENTER);
pane.add(number_key.equal, BorderLayout.SOUTH);
number_key.one.addActionListener(this); // 对1按钮添加监听事件
number_key.two.addActionListener(this); // 对2按钮添加监听事件
number_key.three.addActionListener(this); // 对3按钮添加监听事件
number_key.four.addActionListener(this); // 对4按钮添加监听事件
number_key.five.addActionListener(this); // 对5按钮添加监听事件
number_key.six.addActionListener(this); // 对6按钮添加监听事件
number_key.seven.addActionListener(this); // 对7按钮添加监听事件
number_key.eight.addActionListener(this); // 对8按钮添加监听事件
number_key.nine.addActionListener(this); // 对9按钮添加监听事件
number_key.zero.addActionListener(this); // 对0按钮添加监听事件
number_key.ce.addActionListener(this); // 对置零按钮添加监听事件
number_key.plus.addActionListener(this); // 对+按钮添加监听事件
number_key.equal.addActionListener(this); // 对=按钮添加监听事件
number_key.sub.addActionListener(this); // 对-按钮添加监听事件
number_key.mul.addActionListener(this); // 对*按钮添加监听事件
number_key.div.addActionListener(this); // 对/按钮添加监听事件
number_key.point.addActionListener(this); // 对.按钮添加监听事件
setContentPane(pane);
pack(); // 初始化窗体大小为正好盛放所有按钮
}
// 各个按钮触发的事件
public void actionPerformed(ActionEvent e) {
/*
* 如果是点击数字按钮那么先要判断是否在此之前点击了+、-、*、/、=，如果是那么com=true 如果没有com=
* false;或者是否点击数字键，如果是i = 1,如果没有 i = 0;
*/
if (e.getSource() == number_key.one) {
if (com || i == 0) {
result.text.setText(“1“);
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + “1“);
}
} else if (e.getSource() == number_key.two) {
if (com || i == 0) {
result.text.setText(“2“);
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + “2“);
}
} else if (e.getSource() == number_key.three) {
if (com || i == 0) {
result.text.setText(“3“);
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + “3“);
}
} else if (e.getSource() == number_key.four) {
if (com || i == 0) {
result.text.setText(“4“);
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + “4“);
}
} else if (e.getSource() == number_key.five) {
if (com || i == 0) {
result.text.setText(“5“);
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + “5“);
}
} else if (e.getSource() == number_key.six) {
if (com || i == 0) {
result.text.setText(“6“);
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + “6“);
}
} else if (e.getSource() == number_key.seven) {
if (com || i == 0) {
result.text.setText(“7“);
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + “7“);
}
} else if (e.getSource() == number_key.eight) {
if (com || i == 0) {
result.text.setText(“8“);
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + “8“);
}
} else if (e.getSource() == number_key.nine) {
if (com || i == 0) {
result.text.setText(“9“);
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + “9“);
}
}
/*
* 对于0这个按钮有一定的说法，在我的程序里不会出现如00000这样的情况，我加了判断条件就是
* 如果text中的数值=0就要判断在这个数值中是否有.存在?如果有那么就在原来数值基础之上添 加0;否则保持原来的数值不变
*/
else if (e.getSource() == number_key.zero) { // result.text.getText()是得到text里内容的意思
if (com || i == 0) {
result.text.setText(“0“);
com = false;
i = 1;
} else {
text = result.text.getText();
if (Float.parseFloat(text) 》 0 || Float.parseFloat(text) 《 0) { // Float.parseFloat(text)就是类型转换了，下面都是一样
result.text.setText(text + “0“);
} else {
if (text.trim().indexOf(“.“) == -1) {
result.text.setText(text);
} else {
result.text.setText(text + “0“);
}
}
}
} else if (e.getSource() == number_key.ce) {
result.text.setText(“0“);
i = 0;
com = true;
// text = ““;
defbutton = 0;
}
/*
* 本程序不会让一个数值中出现2个以上的小数点.具体做法是:判断是否已经存在.存在就不添加, 不存在就添加.
*/
else if (e.getSource() == number_key.point) {
if (com || i == 0) {
result.text.setText(“0.“);
com = false;
i = 1;
} else {
text = result.text.getText();
if (text.trim().indexOf(“.“) == -1) {
result.text.setText(text + “.“);
} else {
result.text.setText(text);
}
}
} // 获得点击+之前的数值
else if (e.getSource() == number_key.plus) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
symbol = 1;
} // 获得点击-之前的数值
else if (e.getSource() == number_key.sub) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
symbol = 2;
} // 获得点击*之前的数值
else if (e.getSource() == number_key.mul) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
System.out.println(defbutton);
symbol = 3;
} // 获得点击/之前的数值
else if (e.getSource() == number_key.div) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
symbol = 4;
} else if (e.getSource() == number_key.equal) {
switch (symbol) {
case 1: { // 计算加法
double ad = defbutton
+ Double.parseDouble(result.text.getText());
result.text.setText(ad + ““);
i = 0;
text = ““;
break;
}
case 2: { // 计算减法
double ad = defbutton
- Double.parseDouble(result.text.getText());
result.text.setText(String.valueOf(ad));
i = 0;
text = ““;
break;
}
case 3: { // 计算乘法
double ad = defbutton
* Double.parseDouble(result.text.getText());
result.text.setText(ad + ““);
i = 0;
text = ““;
break;
}
case 4: { // 计算除法
double ad = defbutton
/ Double.parseDouble(result.text.getText());
result.text.setText(ad + ““);
i = 0;
text = ““;
break;
}
}
System.out.println(com);
}
System.out.println(result.text.getText());
}
@SuppressWarnings(“deprecation“)
public static void main(String args) {
Jisuanqi loveyou = new Jisuanqi();
loveyou.show();
}
}
// 计算器数字按钮定义面板
class Number_Key extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
JButton zero = new JButton(“0“); // 数字键0
JButton one = new JButton(“1“); // 数字键1
JButton two = new JButton(“2“); // 数字键2
JButton three = new JButton(“3“); // 数字键3
JButton four = new JButton(“4“); // 数字键4
JButton five = new JButton(“5“); // 数字键5
JButton six = new JButton(“6“); // 数字键6
JButton seven = new JButton(“7“); // 数字键7
JButton eight = new JButton(“8“); // 数字键8
JButton nine = new JButton(“9“); // 数字键9
JButton plus = new JButton(“+“);
JButton sub = new JButton(“-“);
JButton mul = new JButton(“*“);
JButton div = new JButton(“/“);
JButton equal = new JButton(“=“);
JButton ce = new JButton(“清零“); // 置零键
JButton point = new JButton(“.“);
Number_Key() {
setLayout(new GridLayout(4, 4, 1, 1)); // 定义布局管理器为网格布局
setBackground(Color.blue); // 设置背景颜色
// 添加按钮
add(one);
add(two);
add(three);
add(four);
add(five);
add(six);
add(seven);
add(eight);
add(nine);
add(zero);
add(plus);
add(sub);
add(mul);
add(div);
add(point);
add(equal);
add(ce);
}
}
// 计算器显示结果的窗体
class Result extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
// text先是输入和结果
JTextField text = new JTextField(“0“);
@SuppressWarnings(“deprecation“)
Result() { // 讲输入的数字或得到的结果在text的右边显示
text.setHorizontalAlignment(SwingConstants.RIGHT);
text.enable(false); // 文本框不能编辑
setLayout(new BorderLayout()); // 设定布局管理器边框布局
add(text, BorderLayout.CENTER); // text放置在窗体的中间
}
}
直接复制 保存成Jisuanqi .java可以直接运行了
、使用JAVA语言编写一个简易的计算器
我写了个整数可以使用的, 你可以研究一下, 添入小数部分
功能和window7自带的那个一样
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;
public class Caculator extends JFrame {
private JLabel r1;
private JLabel r2;
private int tempResult;
boolean isResult;
private String lastOperator;
public Caculator() {
isResult = true;
tempResult = 0;
lastOperator = “+“;
JPanel jp_main = new JPanel();
jp_main.setLayout(new BorderLayout());
JPanel jp_show = new JPanel();
jp_show.setBorder(new LineBorder(java.awt.Color.black));
jp_show.setLayout(new GridLayout(2, 1));
r1 = new JLabel(“0“, JLabel.RIGHT);
r2 = new JLabel(“0“, JLabel.RIGHT);
jp_show.add(r1);
jp_show.add(r2);
JPanel jp_button = new JPanel();
jp_button.setBorder(new LineBorder(java.awt.Color.black));
jp_button.setLayout(new GridLayout(4, 4));
JButton one = new JButton(“1“);
JButton two = new JButton(“2“);
JButton three = new JButton(“3“);
JButton four = new JButton(“4“);
JButton five = new JButton(“5“);
JButton six = new JButton(“6“);
JButton seven = new JButton(“7“);
JButton eight = new JButton(“8“);
JButton nine = new JButton(“9“);
JButton zero = new JButton(“0“);
JButton dot = new JButton(“.“);
JButton plus = new JButton(“+“);
JButton sub = new JButton(“-“);
JButton multi = new JButton(“*“);
JButton divide = new JButton(“/“);
JButton result = new JButton(“=“);
jp_button.add(one);
jp_button.add(two);
jp_button.add(three);
jp_button.add(sub);
jp_button.add(four);
jp_button.add(five);
jp_button.add(six);
jp_button.add(multi);
jp_button.add(seven);
jp_button.add(eight);
jp_button.add(nine);
jp_button.add(divide);
jp_button.add(zero);
jp_button.add(dot);
jp_button.add(plus);
jp_button.add(result);
JPanel reset = new JPanel();
reset.setBorder(new LineBorder(java.awt.Color.black));
JButton rb = new JButton(“重置“);
rb.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
r1.setText(“0“);
r2.setText(“0“);
isResult = true;
tempResult = 0;
lastOperator = “+“;
}
});
reset.add(rb);
jp_main.add(jp_show, BorderLayout.NORTH);
jp_main.add(jp_button, BorderLayout.CENTER);
jp_main.add(reset, BorderLayout.SOUTH);
this.add(jp_main);
one.addActionListener(new NumberButtonListener());
two.addActionListener(new NumberButtonListener());
three.addActionListener(new NumberButtonListener());
four.addActionListener(new NumberButtonListener());
five.addActionListener(new NumberButtonListener());
six.addActionListener(new NumberButtonListener());
seven.addActionListener(new NumberButtonListener());
eight.addActionListener(new NumberButtonListener());
nine.addActionListener(new NumberButtonListener());
zero.addActionListener(new NumberButtonListener());
// dot.addActionListener(new NumberButtonListener());
plus.addActionListener(new OperatorButtonListener());
sub.addActionListener(new OperatorButtonListener());
multi.addActionListener(new OperatorButtonListener());
divide.addActionListener(new OperatorButtonListener());
result.addActionListener(new ResultButtonListener());
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
this.setSize(370, 280);
this.setResizable(false);
this.setLocationRelativeTo(null);
}
private class NumberButtonListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
JButton jb = (JButton) arg0.getSource();
String temp = r2.getText();
if (!isResult) {
if (temp.equals(“0“)) {
r2.setText(jb.getText());
} else {
r2.setText(temp + jb.getText());
}
} else {
r2.setText(jb.getText());
}
isResult = false;
}
}
private class ResultButtonListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
r1.setText(“0“);
new OperatorButtonListener().caculate(new JButton(“+“));
r2.setText(String.valueOf(tempResult));
isResult = true;
tempResult = 0;
lastOperator = “+“;
}
}
private class OperatorButtonListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
JButton jb = (JButton) arg0.getSource();
String temp1 = r1.getText();
if (temp1.equals(“0“)) {
r1.setText(r2.getText() + “ “ + jb.getText());
caculate(jb);
} else {
r1.setText(temp1 + “ “ + r2.getText() + “ “ + jb.getText());
caculate(jb);
r2.setText(String.valueOf(tempResult));
}
isResult = true;
}
public void caculate(JButton jb){
if(lastOperator.equals(“+“)){
tempResult += Integer.valueOf(r2.getText());
}else if(lastOperator.equals(“-“)){
tempResult -= Integer.valueOf(r2.getText());
}else if(lastOperator.equals(“*“)){
tempResult *= Integer.valueOf(r2.getText());
}else if(lastOperator.equals(“/“)){
tempResult /= Integer.valueOf(r2.getText());
}
lastOperator = jb.getText();
}
}
}
下面是main函数
public class Test {
/**
* @param args
*/
public static void main(String args) {
// TODO Auto-generated method stub
Caculator c = new Caculator();
}
}
你运行就可以看到效果
用JAVA编写一个简单的计算器，要求如下:
然后 通过输入 显示结果，比如说：
以下是上图计算器的代码:
package Computer;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Stack;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Count extends JApplet implements ActionListener
{
/**
*
*/
private static final long serialVersionUID = 1L;
private JTextField textField = new JTextField(“请输入“);
String operator = ““;//操作
String input = ““;//输入的 式子
boolean flag = true;
// boolean flag1 = true;
// boolean flag2 = true;
public void init()//覆写Applet里边的init方法
{
Container C = getContentPane();
JButton b = new JButton;
JPanel panel = new JPanel();
C.add(textField, BorderLayout.NORTH);
C.add(panel,BorderLayout.CENTER);
panel.setLayout(new GridLayout(4, 4,5,5));
String name={“7“,“8“,“9“,“+“,“4“,“5“,“6“,“-“,“1“,“2“,“3“,“*“,“0“,“C“,“=“,“/“};//设置 按钮
for(int i=0;i《16;i++)//添加按钮
{
b[i] = new JButton(name[i]);
b[i].setBackground(new Color(192,192,192));
b[i].setForeground(Color.BLUE);//数字键 设置为 蓝颜色
if(i%4==3)
b[i].setForeground(Color.RED);
b[i].setFont(new Font(“宋体“,Font.PLAIN,16));//设置字体格式
panel.add(b[i]);
b[i].addActionListener(this);
}
b.setForeground(Color.RED);//非数字键，即运算键设置为红颜色
b.setForeground(Color.RED);
}
public void actionPerformed(ActionEvent e)
{
int cnt = 0;
String actionCommand = e.getActionCommand();
if(actionCommand.equals(“+“)||actionCommand.equals(“-“)||actionCommand.equals(“*“) ||actionCommand.equals(“/“))
input +=“ “+actionCommand+“ “;//设置输入，把输入的样式改成 需要的样子
else if(actionCommand.equals(“C“))
input = ““;
else if(actionCommand.equals(“=“))//当监听到等号时，则处理 input
{
input+= “=“+compute(input);
textField.setText(input);
input=““;
cnt = 1;
}
else
input += actionCommand;//数字为了避免多位数的输入 不需要加空格
if(cnt==0)
textField.setText(input);
}
private String compute(String input)//即1237 的 样例
{
String str;
str = input.split(“ “);
Stack《Double》 s = new Stack《Double》();
double m = Double.parseDouble(str);
s.push(m);
for(int i=1;i《str.length;i++)
{
if(i%2==1)
{
if(str[i].compareTo(“+“)==0)
{
double help = Double.parseDouble(str[i+1]);
s.push(help);
}
if(str[i].compareTo(“-“)==0)
{
double help = Double.parseDouble(str[i+1]);
s.push(-help);
}
if(str[i].compareTo(“*“)==0)
{
double help = Double.parseDouble(str[i+1]);
double ans = s.peek();//取出栈顶元素
s.pop();//消栈
ans*=help;
s.push(ans);
}
if(str[i].compareTo(“/“)==0)
{
double help = Double.parseDouble(str[i+1]);
double ans = s.peek();
s.pop();
ans/=help;
s.push(ans);
}
}
}
double ans = 0d;
while(!s.isEmpty())
{
ans+=s.peek();
s.pop();
}
String result = String.valueOf(ans);
return result;
}
public static void main(String args)
{
JFrame frame = new JFrame(“Count“);
Count applet = new Count();
frame.getContentPane().add(applet, BorderLayout.CENTER);
applet.init();//applet的init方法
applet.start();//线程开始
frame.setSize(350, 400);//设置窗口大小
frame.setVisible(true);//设置窗口可见
}
}
如何用java编写一个简单的计算器，只要能进行最基本的加减乘除运算就可以了，本人急用，简单易懂即可，大
简单的啊，我有个自己编的完美的，不过给你改成简单的吧。有注释。
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import java.awt.event.*;
import java.text.*;
public class Calculator extends JFrame implements ActionListener
{
int m=0,i,n=0;
float sum=0,s1,s2,equ;
String v=““;
JPanel delete_main = new JPanel();
JPanel delete = new JPanel();
JPanel buttons = new JPanel();
JTextField text = new JTextField(“0“);
JButton backspace = new JButton(“Backspace“);
JButton c = new JButton(“C“);
JButton ce = new JButton(“CE“);
JButton bt1= new JButton(“1“);
JButton bt2= new JButton(“2“);
JButton bt3= new JButton(“3“);
JButton bt4= new JButton(“+“);
JButton bt5 = new JButton(“4“);
JButton bt6= new JButton(“5“);
JButton bt7= new JButton(“6“);
JButton bt8= new JButton(“-“);
JButton bt9= new JButton(“7“);
JButton bt10= new JButton(“8“);
JButton bt11= new JButton(“9“);
JButton bt12= new JButton(“*“);
JButton bt13= new JButton(“0“);
JButton bt14= new JButton(“.“);
JButton bt15= new JButton(“=“);
JButton bt16= new JButton(“/“);
public Calculator()
{
super(“简易计算器--超人不会飞荣誉出品“);
delete.setLayout(new GridLayout(1, 3, 15, 15));
delete.add(backspace);
delete.add(c);
delete.add(ce);
delete.setBorder(new LineBorder(delete.getBackground(), 5));//添加边框
c.addActionListener(this);
ce.addActionListener(this);
backspace.addActionListener(this);
text.setFont(new Font(“宋体“, Font.BOLD +Font.ITALIC, 20));
// 设置显示字体
text.setBackground(Color.getHSBColor(44, 3, 87));
text.setBorder(new LineBorder(Color.ORANGE, 1));
text.setHorizontalAlignment(SwingConstants.RIGHT); // 设置鼠标靠右
text.setEditable(false); // 屏蔽键盘输入，防止非法字符
delete_main.setLayout(new GridLayout(2, 1, 10, 10));
delete_main.add(text, BorderLayout.NORTH);
delete_main.add(delete, BorderLayout.SOUTH);
buttons.setLayout(new GridLayout(4, 5, 10, 20));
bt1.addActionListener(this); // 为各个按钮添加事件监听
buttons.add(bt1);
bt2.addActionListener(this);
buttons.add(bt2);
bt3.addActionListener(this);
buttons.add(bt3);
bt4.addActionListener(this);
buttons.add(bt4);
bt5.addActionListener(this);
buttons.add(bt5);
bt6.addActionListener(this);
buttons.add(bt6);
bt7.addActionListener(this);
buttons.add(bt7);
bt8.addActionListener(this);
buttons.add(bt8);
bt9.addActionListener(this);
buttons.add(bt9);
bt10.addActionListener(this);
buttons.add(bt10);
bt11.addActionListener(this);
buttons.add(bt11);
bt12.addActionListener(this);
buttons.add(bt12);
bt13.addActionListener(this);
buttons.add(bt13);
bt14.addActionListener(this);
buttons.add(bt14);
bt15.addActionListener(this);
buttons.add(bt15);
bt16.addActionListener(this);
buttons.add(bt16);
buttons.setBorder(new LineBorder(delete.getBackground(), 5));//边框
this.setLayout(new BorderLayout());
this.add(delete_main, BorderLayout.NORTH);
this.add(buttons, BorderLayout.SOUTH);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //添加关闭窗口事件监听器
pack(); //自动设置窗体大小
setResizable(false); // 设置面板大小不可变
setVisible(true);
Toolkit tk = this.getToolkit();
Dimension de = tk.getScreenSize();
setBounds((de.width - this.getWidth()) / 2,(de.height - this.getHeight()) / 2, this.getWidth(), this.getHeight());
//使之居于屏幕正中央
}
public void actionPerformed(ActionEvent e)
{ //事件响应
//Object source = e.getSource();
if(e.getSource()==backspace) //退格键
{
v=v.substring(0,v.length() - 1);
text.setText(v);
}
if(e.getSource()==c||e.getSource()==ce) //清空键
{
m=0;
sum=0;
v=““;s1=0;s2=0;i=0;
text.setText(“0“);
}
if(e.getSource()==bt1)
{
if(m==1)
v=““;
v=v+“1“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt2)
{
if(m==1)
v=““;
v=v+“2“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt3)
{
if(m==1)
v=““;
v=v+“3“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt4) // +按钮
{
if(n==1) //如果按之前按了0~9数字键，就运算
{
sum=Float.parseFloat(v);
}
else //如果按之前没按0~9数字键，直接按了运算符，不做任何操作
{
}
i=1;
m=1;n=0;
}
if(e.getSource()==bt5)
{
if(m==1)
v=““;
v=v+“4“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt6)
{
if(m==1)
v=““;
v=v+“5“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt7)
{
if(m==1)
v=““;
v=v+“6“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt8) // -按钮
{
if(n==1)
{
sum=Float.parseFloat(v);
}
else
{
}
i=2;
m=1;n=0;
}
if(e.getSource()==bt9)
{
if(m==1)
v=““;
v=v+“7“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt10)
{
if(m==1)
v=““;
v=v+“8“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt11)
{
if(m==1)
v=““;
v=v+“9“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt12) //*按钮
{
if(n==1)
{
sum=Float.parseFloat(v);
}
else
{
}
i=3;
m=1;n=0;
}
if(e.getSource()==bt13)
{
if(m==1)
v=““;
v=v+“0“;
text.setText(v);
m=0;n=1;
}
if(e.getSource()==bt14)
{
}
if(e.getSource()==bt15) //等于按钮
{
if(m==1) // 如果输入了+=等非法输入，不做任何操作
{ }
else
{
s1=sum;
s2=Float.parseFloat(v);
switch(i)
{
case 0: //如果按过数字键后直接按等号，直接输出
equ=Float.parseFloat(v);
break;
case 1:
equ=s1+s2;
break;
case 2:
equ=s1-s2;
break;
case 3:
equ=s1*s2;
break;
case 4:
equ=s1/s2;
break;
}
sum=0;v=““; //清空运算数
v=String.valueOf(equ);
text.setText(String.valueOf(equ));
i=0;
}
}
if(e.getSource()==bt16) // 除按钮
{
if(n==1)
{
sum=Float.parseFloat(v);
}
else
{
}
i=4;
m=1;n=0;
}
}
public static void main(String args)
{
Calculator bt=new Calculator();
}
}
用java编写简易计算器
package calc; import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*; public class Caculator {
private JFrame jf;
private JButton jbs;
private JTextField jtf;
private JButton clear;
private double num1, num2, rs;
private char c;
/**
* 构造方法实例化属性
*/
public Caculator() {
jf = new JFrame(“简易计算器“);
jtf = new JTextField(20);
clear = new JButton(“clear“);
jbs = new JButton;
String str = “123+456-789*0./=“;
for (int i = 0; i 《 str.length(); i++) {
jbs[i] = new JButton(str.charAt(i) + ““);
}
init();
addEventHandler();
showMe();
}
/**
* 布局图形界面
*/
public void init() {
JPanel jp1 = new JPanel();
jp1.add(jtf); JPanel jp2 = new JPanel();
jp2.setLayout(new GridLayout(4, 4));
for (int i = 0; i 《 16; i++) {
jp2.add(jbs[i]);
}
JPanel jp3 = new JPanel();
jp3.add(clear);
jf.add(jp1, BorderLayout.NORTH);
jf.add(jp2, BorderLayout.CENTER);
jf.add(jp3, BorderLayout.SOUTH);
} public void setFont() { }
public void setColor() { }
public void addEventHandler() {
ActionListener lis = new ActionListener() {
public void actionPerformed(ActionEvent e) {
JButton jb = (JButton) e.getSource();
String str = jb.getText().trim();// 把字符串的首尾空格去掉！
if (“0123456789.“.indexOf(str) != -1) {// 如果是数字或点号
jtf.setText(jtf.getText() + str);
return;
}
if (“+-*/“.indexOf(str) != -1) {
num1 = Double.parseDouble(jtf.getText());
jtf.setText(““);
c = str.charAt(0);
jtf.setText(““);
return;
}
if (str.equals(“=“)) {
num2 = Double.parseDouble(jtf.getText());
switch (c) {
case ’+’:
rs = num1 + num2;
break;
case ’-’:
rs = num1 - num2;
break;
case ’*’:
rs = num1 * num2;
break;
case ’/’:
rs = num1 / num2;
break;
}
jtf.setText(Double.toString(rs));
return;
}
if (e.getActionCommand().equals(“clear“)) {
jtf.setText(““);
return;
}
}
};
for (int i = 0; i 《 jbs.length; i++) { jbs[i].addActionListener(lis);
}
clear.addActionListener(lis);
}
public void showMe() {
jf.pack();
jf.setVisible(true);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String args) {
new Caculator();
}
}
呃.貌似有小Bug..自己改进一下吧..好运哈..
用java编写简单计算器
这个是我以前写的一个程序 我把里边没用的注掉了 如果你想添加其他功能 把注释解开就行了
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Calculator extends JFrame {
private Container container;
private GridBagLayout layout;
private GridBagConstraints constraints;
private JTextField displayField;// 计算结果显示区
private String lastCommand;// 保存+,-,*,/,=命令
private double result;// 保存计算结果
private boolean start;// 判断是否为数字的开始
public Calculator() {
super(“Calculator“);
container = getContentPane();
layout = new GridBagLayout();
container.setLayout(layout);
constraints = new GridBagConstraints();
start = true;
result = 0;
lastCommand = “=“;
displayField = new JTextField(20);
displayField.setHorizontalAlignment(JTextField.RIGHT);
constraints.gridx = 0;
constraints.gridy = 0;
constraints.gridwidth = 4;
constraints.gridheight = 1;
constraints.fill = GridBagConstraints.BOTH;
constraints.weightx = 100;
constraints.weighty = 100;
layout.setConstraints(displayField, constraints);
container.add(displayField);
ActionListener insert = new InsertAction();
ActionListener command = new CommandAction();
// addButton(“Backspace“, 0, 1, 2, 1, insert);
// addButton(“CE“, 2, 1, 1, 1, insert);
// addButton(“C“, 3, 1, 1, 1, insert);
addButton(“7“, 0, 2, 1, 1, insert);
addButton(“8“, 1, 2, 1, 1, insert);
addButton(“9“, 2, 2, 1, 1, insert);
addButton(“/“, 3, 2, 1, 1, command);
addButton(“4“, 0, 3, 1, 1, insert);
addButton(“5“, 1, 3, 1, 1, insert);
addButton(“6“, 2, 3, 1, 1, insert);
addButton(“*“, 3, 3, 1, 1, command);
addButton(“1“, 0, 4, 1, 1, insert);
addButton(“2“, 1, 4, 1, 1, insert);
addButton(“3“, 2, 4, 1, 1, insert);
addButton(“-“, 3, 4, 1, 1, command);
addButton(“0“, 0, 5, 1, 1, insert);
// addButton(“+/-“, 1, 5, 1, 1, insert);// 只显示“-“号,“+“没有实用价值
addButton(“.“, 2, 5, 1, 1, insert);
addButton(“+“, 3, 5, 1, 1, command);
addButton(“=“, 0, 6, 4, 1, command);
this.setResizable(false);
setSize(180, 200);
setVisible(true);
}
private void addButton(String label, int row, int column, int with,
int height, ActionListener listener) {
JButton button = new JButton(label);
constraints.gridx = row;
constraints.gridy = column;
constraints.gridwidth = with;
constraints.gridheight = height;
constraints.fill = GridBagConstraints.BOTH;
button.addActionListener(listener);
layout.setConstraints(button, constraints);
container.add(button);
}
private class InsertAction implements ActionListener {
public void actionPerformed(ActionEvent event) {
String input = event.getActionCommand();
if (start) {
displayField.setText(““);
start = false;
if (input.equals(“+/-“))
displayField.setText(displayField.getText() + “-“);
}
if (!input.equals(“+/-“)) {
if (input.equals(“Backspace“)) {
String str = displayField.getText();
if (str.length() 》 0)
displayField
.setText(str.substring(0, str.length() - 1));
} else if (input.equals(“CE“) || input.equals(“C“)) {
displayField.setText(“0“);
start = true;
} else
displayField.setText(displayField.getText() + input);
}
}
}
private class CommandAction implements ActionListener {
public void actionPerformed(ActionEvent evt) {
String command = evt.getActionCommand();
if (start) {
lastCommand = command;
} else {
calculate(Double.parseDouble(displayField.getText()));
lastCommand = command;
start = true;
}
}
}
public void calculate(double x) {
if (lastCommand.equals(“+“))
result += x;
else if (lastCommand.equals(“-“))
result -= x;
else if (lastCommand.equals(“*“))
result *= x;
else if (lastCommand.equals(“/“))
result /= x;
else if (lastCommand.equals(“=“))
result = x;
displayField.setText(““ + result);
}
public static void main(String args) {
Calculator calculator = new Calculator();
calculator.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
JAVA编写简单的计算器
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Test implements ActionListener {
String str;
String fuhao;
double count1 = 0;
double count2 = 0;
JFrame jf = new JFrame(“计算器“);
JTextField jtf = new JTextField(10);
int a, b;
public Test() {
JPanel jp = new JPanel();
String lab = { “backs“, “ce“, “c“, “=“, “7“, “8“, “9“, “+“, “4“, “5“,
“6“, “-“, “1“, “2“, “3“, “*“, “0“, “.“, “+/-“, “/“ };
jp.setLayout(new GridLayout(5, 4));
JButton jb = new JButton[lab.length];
jf.add(jtf, BorderLayout.NORTH);
for (int i = 0; i 《 jb.length; i++) {
jb[i] = new JButton(lab[i]);
jp.add(jb[i]);
}
for (int i = 0; i 《 20; i++) {
jb[i].addActionListener(this);
}
jf.add(jp);// 默认放在center
jf.setSize(300, 200);
jf.setLocation(350, 250);
jf.setResizable(false);
jf.setVisible(true);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void actionPerformed(ActionEvent ae) {
String com = ae.getActionCommand();
double result = 0;
if (com.equals(“+/-“)) {
jtf.setText(“-“ + jtf.getText());
}
if (com.equals(“backs“)) {
String s = jtf.getText();
if (str.length() 》 0) {
jtf.setText(s.substring(0, s.length() - 1));
}
}
if (com.equals(“ce“) || com.equals(“c“)) {
jtf.setText(“0“);
}
if (“+“.equals(com)) {
fuhao = com;
count1 = Double.parseDouble(jtf.getText());
str = jtf.getText() + com;
jtf.setText(str);
}
if (“-“.equals(com)) {
fuhao = com;
count1 = Double.parseDouble(jtf.getText());
str = jtf.getText() + com;
jtf.setText(str);
}
if (“*“.equals(com)) {
fuhao = com;
count1 = Double.parseDouble(jtf.getText());
str = jtf.getText() + com;
jtf.setText(str);
}
if (“/“.equals(com)) {
fuhao = com;
count1 = Double.parseDouble(jtf.getText());
str = jtf.getText() + com;
jtf.setText(str);
}
if (“0“.equals(com) || “1“.equals(com) || “2“.equals(com)
|| “3“.equals(com) || “4“.equals(com) || “5“.equals(com)
|| “6“.equals(com) || “7“.equals(com) || “8“.equals(com)
|| “9“.equals(com)) {
jtf.setText(jtf.getText() + com);
}
if (“=“.equals(com)) {
str = jtf.getText() + com;
count2 = Double.parseDouble(str.substring(str.indexOf(fuhao) + 1,
str.length() - 1));
if (“+“.equals(fuhao))
result = count1 + count2;
if (“-“.equals(fuhao))
result = count1 - count2;
if (“*“.equals(fuhao))
result = count1 * count2;
if (“/“.equals(fuhao))
result = count1 / count2;
jtf.setText(result + ““);
}
}
// TODO Auto-generated method stub
public static void main(String args) {
new Test();
}
}
怎么用JAVA编程编写一个计算器
打开IED：打开自己java编程的软件，采用的是eclipse软件。
建立java工程。
编写类。
编写类的详细步骤
1.类的基本结构：
由于这里用到了界面，所以要进行窗口界面的编程，按钮事件的处理，和计算处理界面；
package MyCaculator;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyCaculator extends JFrame {
private int add=1,sub=2,mul=3,div=4;
private int op=0;
boolean ifOp;
private String output=“0“;
private Button jba=new Button{new Button(“7“),new Button(“8“),
new Button(“9“),new Button(“+“),
new Button(“4“),new Button(“5“),new Button(“6“),new Button(“-“),
new Button(“1“),new Button(“2“),new Button(“3“),new Button(“*“),
new Button(“0“),new Button(“.“),new Button(“=“),new Button(“/“)};
private JPanel jpt=new JPanel();
private JPanel jpb=new JPanel();
private JTextField jtf=new JTextField(““);
private MyCaculator(){
}
private void operate(String x){
}
public String add(String x){
return output;
}
public String subtract(String x){
return output;
}
public String multiply(String x){
return output;
}
public String divide(String x){
return output;
}
public String Equals(String x){
return output;
}
public void opClean(){
}
class setOperate_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
}
}
class setLabel_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
}
}
public static void main(String args) {
}
}
2.建立构造方法：
所谓构造方法就是，对自己的主类进行初始化，代码如下：
private MyCaculator(){
jpt.setLayout(new BorderLayout());
jpt.add(jtf);
this.add(jpt,BorderLayout.NORTH);
jpb.setLayout(new GridLayout(4,4));
for(int i=0;i《jba.length;i++){
jpb.add(jba[i]);
if(i==3||i==7||i==11||i==15||i==14)
jba[i].addActionListener(new setOperate_Act());
else
jba[i].addActionListener(new setLabel_Act());
}
this.add(jpb,BorderLayout.CENTER);
this.setSize(250, 200);
this.setResizable(false);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
3.建立数据计算方法
这里的数据计算方法有6个，一个是主方法其他几个是加减乘除的处理方法，代码如下：
private void operate(String x){
double x1=Double.valueOf(x);
double y=Double.valueOf(output);
switch(op){
case 0:output=x;break;
case 1:output=String.valueOf(y+x1);break;
case 2:output =String.valueOf(y-x1);break;
case 3:output =String.valueOf(y*x1);break;
case 4:
if(x1!=0) output=String.valueOf(y/x1);
elseoutput=“不能为0“;
break;
}
}
public String add(String x){
operate(x);
op=add;
return output;
}
public String subtract(String x){
operate(x);
op=sub;
return output;
}
public String multiply(String x){
operate(x);
op=mul;
return output;
}
public String divide(String x){
operate(x);
op=div;
return output;
}
public String Equals(String x){
operate(x);
op=0;
return output;
}
public void opClean(){
op=0;
output =“0“;
}
4.事件处理方法
这里的时间处理方法，没有建立一个整体的方法，二是在为了便于处理的方法，将按钮事件分成两个部分，并采用两个子类来实现，这两个类时内部类要写在主类内部的，代码如下：
class setOperate_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
if(e.getSource()==jba){
jtf.setText(add(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba){
jtf.setText(subtract(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba){
jtf.setText(multiply(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba){
jtf.setText(divide(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba){
jtf.setText(Equals(jtf.getText()));
ifOp=true;
}
}
}
class setLabel_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
Button tempb=(Button)e.getSource();
if(ifOp){
jtf.setText(tempb.getLabel());
ifOp=false;
}else {
jtf.setText(jtf.getText()+tempb.getLabel());
}
}
}
5.建立main方法：
要想实现我们的代码，我们需在main方法中，实例化我们的对象。
public static void main(String args) {
new MyCaculator();
}
