Java简易计算器

1、简易计算器总结1、计算器设计背景日常生活中我们经常会遇到一些小型数据计算的问题，本课程就是以此为出发点，设计了这样一个简单的计算器，用以实现基本的数学运算。在java语言当中通过定义类，类中的各种方法实现对计算器相关功能的实现，并通过与用户自己手动输入并选择运算功能实现计算功能，是一个完全由用户控制的简易计算器。 2、需求环境硬件要求：一台计算机。软件配置：WINDOWS系统、JDK 1.7、myeclipse 3、 计算器设计思路计算器最主要的就是实用性，要简单，便于操作。程序界面是一个窗口的形式展现并由用户自己完全手动控制。并以设计的要求为基础，在实现课程设计

2、所给的功能以外，要对界面的美观进行了优化，看起来更人性化。4、计算器实现代码package com.cqeec.sc;import java.awt.BorderLayout;import java.awt.Color;import java.awt.Dimension;import java.awt.Font;import java.awt.GridLayout;import java.awt.Insets;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.

3、KeyEvent;import javax.swing.BorderFactory;import javax.swing.ImageIcon;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JMenu;import javax.swing.JMenuBar;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.JTextField;import jav

4、ax.swing.border.BevelBorder;public class Calculator extends JFrame private static final long serialVersionUID = 1L;/ 定义一级菜单名称private final String ONE_MENU_NAME = "编辑(E)", "查看(V)", "帮助(H)" ;/ 定义一级菜单的热键private final int ONE_MENU_MNEMONIC = KeyEvent.VK_E, KeyEvent.VK_V,Key

5、Event.VK_H ;/ 定义菜单private JMenu oneMenu;/ 定义显示器private JTextField display;/ 定义左边面板MC、MR、MS、M+操作按钮标签private static final String BUTTON_MX_NAME = "MC", "MR", "MS", "M+" ;/ 定义左边面板MC、MR、MS、M+操作按钮private JButton buttonMX;/ 定义清除系列按钮标签private static final String BUTT

6、ON_CLEAR_NAME = "Backspace", "CE", "C" ;/ 定义清除系统按钮private JButton buttonClear;/ 定义数字,运算符,功能等按钮private static final String BUTTON_AN_NAME = "1/x", "log", "7", "8","9", "÷", "n!", "sqrt",

7、 "4", "5", "6", "×", "sin", "x2", "1", "2","3", "-", "cos", "x3", "0", "±", ".", "+", "tan", "%", ""

8、, "e","' "", "=" ;private JButton buttonAN;/ M的值private double m;/ 计算器标签，同时也用于显示M变量的值private JLabel labelCalculator;/ 结果private double result;/ 标志量，true表示开始新的输入，false表示不是private boolean isStratNewInput;/ 保存运算符private String operator = "="public Calcul

9、ator() / 创建窗体this.setFrame();/ 创建菜单this.createMenu();private void setFrame() / 设置窗体标题this.setTitle("计算器");/ 改变大小this.setSize(500, 400);/ 使窗体居于屏幕中间this.setLocationRelativeTo(null);/ 设置窗体的默认关闭操作this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);/ 让窗体不能改变大小this.setResizable(false);/ 更改窗体的图标t

10、his.setIconImage(new ImageIcon("images/jisuanqi.jpg").getImage();private void createMenu() JMenuBar menuBar = new JMenuBar();/ 创建菜单oneMenu = new JMenuONE_MENU_NAME.length;/ 通过循环将一级菜单创建出来并添加到菜单栏for (int i = 0; i < ONE_MENU_NAME.length; i+) / 创建一级菜单并保存到数组oneMenui = new JMenu(ONE_MENU_NAME

11、i);/ 设置一级菜单栏热键oneMenui.setMnemonic(ONE_MENU_MNEMONICi);/ 将一级菜单添加到菜单栏menuBar.add(oneMenui);/ 将菜单栏添加到窗体this.setJMenuBar(menuBar);/ 获取窗体的内容面板的布局管理器BorderLayout layout = (BorderLayout) this.getContentPane().getLayout();/ 设置垂直间距layout.setVgap(5);/ 创建显示器display = new JTextField("0");/ 右对齐display

12、.setHorizontalAlignment(JTextField.RIGHT);/ 设置字体大小display.setFont(new Font("", Font.ITALIC, 38);/ 设置禁用显示器display.setEnabled(false);/ 设置显示器与文本距离display.setMargin(new Insets(5, 0, 5, 5);/ 设置显示器位置this.add(display, BorderLayout.NORTH);/ 创建左边面板JPanel leftPanel = new JPanel(new GridLayout(5, 1,

13、0, 5);/ 设置面板的宽度leftPanel.setPreferredSize(new Dimension(80, 80);/ 创建计算器标签labelCalculator = new JLabel("计算器");/ 设置标签文字居中对齐labelCalculator.setHorizontalAlignment(JLabel.CENTER);/ 设置计算器标签凹下去的效果labelCalculator.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED);/ 将计算器面板添加到左面板上leftPa

14、nel.add(labelCalculator);MAction mAction = new MAction();/ 创建M系列按钮/ 分配M系列按钮数组大小buttonMX = new JButtonBUTTON_MX_NAME.length;/ 循环创建M系列按钮for (int n = 0; n < BUTTON_MX_NAME.length; n+) / 创建按钮并存入数组中buttonMXn = new JButton(BUTTON_MX_NAMEn);/ 设置按钮不要焦点框buttonMXn.setFocusable(false);/ 设置按钮前景色buttonMXn.set

15、Foreground(Color.red);/ 设置按钮动作命令buttonMXn.setActionCommand(BUTTON_MX_NAMEn);buttonMXn.addActionListener(mAction);/ 添加按钮动作监听buttonMXn.addActionListener(mAction);if (n = 0 | n = 1) buttonMXn.setEnabled(false);/ 将按钮添加到左面板上leftPanel.add(buttonMXn);/ 将左面板添加到窗体的左边this.add(leftPanel, BorderLayout.WEST);/ 定

16、义右面板JPanel rightPanel = new JPanel(new BorderLayout(0, 5);/ 定义Backspace、CE、C按钮Clear clearProcess = new Clear();JPanel topPanel = new JPanel(new GridLayout(1, 3, 6, 0);topPanel.setPreferredSize(new Dimension(0, 40);buttonClear = new JButtonBUTTON_CLEAR_NAME.length;for (int i = 0; i < BUTTON_CLEAR_

17、NAME.length; i+) buttonCleari = new JButton(BUTTON_CLEAR_NAMEi);buttonCleari.setFocusable(false);buttonCleari.setForeground(Color.BLACK);buttonCleari.setActionCommand(BUTTON_CLEAR_NAMEi);buttonCleari.addActionListener(clearProcess);topPanel.add(buttonCleari);/ 将Backspace、CE、C按钮面板放到右面板北边rightPanel.ad

18、d(topPanel, BorderLayout.NORTH);/ 定义数字按钮事件处理程序类对象NumAction numAction = new NumAction();SignAction signAction = new SignAction();/ 定义数字、运算符、功能等按钮JPanel bottomPanel = new JPanel(new GridLayout(5, 6, 8, 8);buttonAN = new JButtonBUTTON_AN_NAME.length;for (int i = 0; i < BUTTON_AN_NAME.length; i+) but

19、tonANi = new JButton(BUTTON_AN_NAMEi);buttonANi.setFocusable(false);/ 设置按钮动作命令buttonANi.setActionCommand(BUTTON_AN_NAMEi);/ 为数字按钮添加监听if ("0123456789±".contains(BUTTON_AN_NAMEi) buttonANi.addActionListener(numAction);if (".".equals(BUTTON_AN_NAMEi) buttonANi.addActionListener

20、(new DotAction();/ 定义按钮文字颜色if ("÷×-+=".indexOf(BUTTON_AN_NAMEi) >= 0) buttonANi.setForeground(Color.RED);buttonANi.addActionListener(signAction); else if ("e' "".indexOf(BUTTON_AN_NAMEi) >= 0) buttonANi.setForeground(Color.YELLOW);buttonANi.addActionListe

21、ner(signAction); else if ("0123456789±.".indexOf(BUTTON_AN_NAMEi) >= 0) buttonANi.setForeground(Color.BLUE);buttonANi.setActionCommand(BUTTON_AN_NAMEi);buttonANi.addActionListener(signAction); else buttonANi.setForeground(Color.MAGENTA);buttonANi.setActionCommand(BUTTON_AN_NAMEi);b

22、uttonANi.addActionListener(signAction);bottomPanel.add(buttonANi);/ 将数字、运算符、功能等按钮面板放到右面板的中间rightPanel.add(bottomPanel, BorderLayout.CENTER);/ 将右面板添加到窗体this.add(rightPanel, BorderLayout.CENTER);/ 显示窗体this.setVisible(true);/* * 数字、±（正负号）按钮事件处理程序类 */class NumAction implements ActionListener public

23、 void actionPerformed(ActionEvent e) / 获取事件源对象传过来的动作命令String cmd = e.getActionCommand();if (isStratNewInput) display.setText("");isStratNewInput = false;if ("±".equals(cmd) / 正负号if ("0".equals(display.getText() display.setText("-"); else double num;String

24、 strNum = display.getText();if (strNum.contains(".") num = Double.parseDouble(strNum) * -1;strNum = String.valueOf(num); else num = Double.parseDouble(strNum) * -1;strNum = String.valueOf(num);if (strNum.contains("E") else strNum = strNum.substring(0, strNum.length() - 2);display

25、.setText(strNum); else / 数字if ("0".equals(display.getText() display.setText("");display.setText(display.getText() + cmd);/* * 小数点按钮事件处理程序 */class DotAction implements ActionListener public void actionPerformed(ActionEvent e) if (!display.getText().contains(".") display.

26、setText(display.getText() + ".");/* * Backspace、CE、C按钮事件处理程序类 */class Clear implements ActionListener public void actionPerformed(ActionEvent e) String cmd = e.getActionCommand();if ("Backspace".equals(cmd) / 删除一个String strNum = display.getText();if (strNum.length() = 0 | "0

27、".equals(strNum) strNum = "0" else strNum = strNum.substring(0, strNum.length() - 1);strNum = "".equals(strNum) ? "0" : strNum;display.setText(strNum); else if ("CE".equals(cmd) / 清除显示器上的数字，显示零display.setText("0"); else if ("C".equals(

28、cmd) / 清除M存储的值和显示器上的数字，显示零display.setText("0");labelCalculator.setText("计算器");m = 0;result = 0;isStratNewInput = false;/* * MC、MR、MS、M+按钮事件处理程序类 */class MAction implements ActionListener public void actionPerformed(ActionEvent e) String cmd = e.getActionCommand();if ("MC&quo

29、t;.equals(cmd) labelCalculator.setText("计算器");m = 0;buttonMX0.setEnabled(false);buttonMX1.setEnabled(false); else if ("MR".equals(cmd) String strM = String.valueOf(m);if (strM.charAt(strM.length() - 1) = '0') strM = strM.substring(0, strM.length() - 2);display.setText(str

30、M); else if ("MS".equals(cmd) String strNum = display.getText();m = Double.parseDouble(strNum);strNum = String.valueOf(m);if (strNum.charAt(strNum.length() - 1) = '0') strNum = strNum.substring(0, strNum.length() - 2);labelCalculator.setText(String.valueOf(m);buttonMX0.setEnabled(t

31、rue);buttonMX1.setEnabled(true); else if ("M+".equals(cmd) m = m + m;labelCalculator.setText(String.valueOf(m);buttonMX0.setEnabled(true);buttonMX1.setEnabled(true);class SignAction implements ActionListener public void actionPerformed(ActionEvent e) String cmd = e.getActionCommand();doubl

32、e num = Double.parseDouble(display.getText();if ("1/x".equals(cmd) if (num = 0) / 弹出提示JOptionPane.showMessageDialog(null,"<html>分母<span style="color:red;">不能</span>为零！</html>","错误", JOptionPane.ERROR_MESSAGE); else display.setText(Strin

33、g.valueOf(1 / num); else if ("log".equals(cmd) if (num <= 0) / 弹出提示JOptionPane.showMessageDialog(null, "输入的指数必须大于零", "错误",JOptionPane.ERROR_MESSAGE); else display.setText(String.valueOf(Math.log(num); else if ("n!".equals(cmd) if (num < 0) JOptionPane.sh

34、owMessageDialog(null, "计算阶乘的数不能小于零", "错误",JOptionPane.ERROR_MESSAGE); else double s = 1;for (int i = 1; i < num; i+) s *= i;display.setText(String.valueOf(s); else if ("sqrt".equals(cmd) if (num <= 0) / 弹出提示JOptionPane.showMessageDialog(null, "输入的数必须大于零"

35、, "错误",JOptionPane.ERROR_MESSAGE); else display.setText(String.valueOf(Math.sqrt(num); else if ("sin".equals(cmd) display.setText(String.valueOf(Math.sin(num); else if ("x2".equals(cmd) display.setText(String.valueOf(Math.pow(num, 2); else if ("cos".equals(cmd

36、) display.setText(String.valueOf(Math.cos(num); else if ("x3".equals(cmd) display.setText(String.valueOf(Math.pow(num, 3); else if ("tan".equals(cmd) display.setText(String.valueOf(Math.tan(num); else if ("%".equals(cmd) num = num / 100;display.setText(String.valueOf(nu

37、m); else if ("".equals(cmd) display.setText(String.valueOf(Math.PI); else if ("e".equals(cmd) String strNum = display.getText();if (strNum.contains(".") String strZS;/ 小数strNum = String.valueOf(Double.parseDouble(strNum);if (strNum.contains("E") display.setTex

38、t(strNum.replace('E', 'e'); else / 取整数部分strZS = strNum.substring(0, strNum.indexOf(".");/ 判断小数的整数部分长度是否大于1strZS = String.valueOf(Math.abs(Long.parseLong(strZS);if (strZS.length() > 1) / 左移小数点strZS = strZS.substring(0, 1)+ "."+ strZS.substring(1, strZS.length()+

39、 strNum.substring(strNum.indexOf(".") + 1,strNum.length() + "e+"+ (strZS.length() - 1);if (strNum.contains("-") strZS = "-" + strZS;display.setText(strZS); else if ("0".equals(strZS) | "-0".equals(strZS) / 取出小数部分String strXS = strNum.substr

40、ing(strNum.indexOf(".") + 1,strNum.length();/ 统计小数点后零的个数+1(次方数)int count = 0;for (int i = 0; strXS.charAt(i) = '0' i+) count+;count = count + 1;/ 取出底数strXS = String.valueOf(Long.parseLong(strXS);strXS = strXS.substring(0, 1) + "."+ strXS.substring(1, strXS.length();/ 连接strNum = strXS + "e-" + count; else / 不动strNum = strNum + "e+0"display.setText(strNum); else / 不是小数double ds;if (strNum.contains("-") ds = Double.pa