JAVA编写的计算器程序源代码

import java.awt.*; import java.lang.*; import javax.swing.*; import javax.swing.event.*; import java.awt.event.*; import java.text.DecimalFormat; public class Calculator implements ActionListener { //导入动作监听接口 //设计面板中的单位 JFrame frame;//主窗口 JTextField textAnswer;//显示文本框 JPanel panel, panel1, panel2, panel3; JMenuBar mainMenu; JTextField textMemory; JLabel labelMemSpace; //labelMemSpace单纯做摆设，控制面板的形状 JButton buttonBk, buttonCe, buttonC; JButton button[]; JButton buttonMC, buttonMR, buttonMS, buttonMAdd; JButton buttonDot, buttonAddAndSub, buttonAdd, buttonSub, buttonMul, buttonDiv, buttonMod; JButton buttonSqrt, buttonDao, buttonEqual; JMenu viewMenu, helpMenu; JMenuItem tItem, sItem, topHelp, aboutCal; DecimalFormat df; //设置数据输出精度 boolean clickable; //控制当前能否按键 double memoryd; //使用内存中存储的数字 int memoryi; double vard, answerd; //用来保存double型数据的中间值(vard)和最后结果(answerd) short key = -1, prekey = -1; //key用来保存当前进行何种运算,prekey用来保存前次进行何种运算 String copy; //做复制用 JTextArea help; //帮助 JScrollPane scrollHelp; //构造函数 public Calculator() { clickable = true; answerd = 0; frame = new JFrame("计算器"); df = new DecimalFormat("0.00000000"); //设置数据输出精度(对于double型值) textAnswer = new JTextField(15); textAnswer.setText(""); textAnswer.setHorizontalAlignment(JTextField.RIGHT); textAnswer.setBorder(BorderFactory.createLineBorder(Color.red)); textAnswer.setEditable(false); textAnswer.setBackground(new Color(255, 255, 255)); panel = new JPanel(); frame.getContentPane().add(panel); panel1 = new JPanel(); panel2 = new JPanel(); panel.setLayout(new BorderLayout()); //设计整个面板 mainMenu = new JMenuBar(); viewMenu = new JMenu("查看(V)"); helpMenu = new JMenu("帮助(H)"); tItem = new JMenuItem("●标准型(T)"); tItem.addActionListener(this); sItem = new JMenuItem("●科学型(S)"); sItem.addActionListener(this); viewMenu.add(tItem); viewMenu.add(sItem); topHelp = new JMenuItem(" 帮助主题(H)"); topHelp.addActionListener(this); help = new JTextArea(5, 20); scrollHelp = new JScrollPane(help); help.setEditable(false); help.append("执行简单计算\n"); help.append("1. 键入计算的第一个数字。\n"); help.append("2. 单击“+”执行加、“-”执行减、“*”执行乘或“/”执行除。\n"); help.append("3. 键入计算的下一个数字。\n"); help.append("4. 输入所有剩余的运算符和数字。\n"); help.append("5. 单击“=”。\n"); aboutCal = new JMenuItem(" 关于计算器(A)"); aboutCal.addActionListener(this); helpMenu.add(topHelp); helpMenu.add(aboutCal); mainMenu.add(viewMenu); mainMenu.add(helpMenu); panel.add(mainMenu, BorderLayout.NORTH); panel.add(textAnswer, BorderLayout.CENTER); panel.add(panel1, BorderLayout.SOUTH); panel1.setLayout(new BorderLayout()); textMemory = new JTextField(3); textMemory.setEditable(false); textMemory.setBackground(new Color(217, 217, 217)); labelMemSpace = new JLabel(" "); buttonBk = new JButton("Backspace"); buttonBk.setForeground(new Color(255, 0, 0)); buttonCe = new JButton("CE"); buttonCe.setForeground(new Color(255, 0, 0)); buttonC = new JButton("C"); buttonC.setForeground(new Color(255, 0, 0)); buttonBk.addActionListener(this); buttonCe.addActionListener(this); buttonC.addActionListener(this); panel1.add(panel2, BorderLayout.NORTH); panel2.setLayout(new FlowLayout(FlowLayout.RIGHT)); panel2.add(textMemory); panel2.add(labelMemSpace); panel2.add(buttonBk); panel2.add(buttonCe); panel2.add(buttonC); panel3 = new JPanel(); panel1.add(panel3, BorderLayout.CENTER); button = new JButton[10]; for (int i = 0; i < button.length; i++) { button[i] = new JButton(Integer.toString(i)); button[i].setForeground(new Color(0, 0, 255)); } buttonMC = new JButton("MC"); buttonMC.setForeground(new Color(255, 0, 0)); buttonMR = new JButton("MR"); buttonMR.setForeground(new Color(255, 0, 0)); buttonMS = new JButton("MS"); buttonMS.setForeground(new Color(255, 0, 0)); buttonMAdd = new JButton("M+"); buttonMAdd.setForeground(new Color(255, 0, 0)); buttonDot = new JButton("."); buttonDot.setForeground(new Color(0, 0, 255)); buttonAddAndSub = new JButton("+/-"); buttonAddAndSub.setForeground(new Color(0, 0, 255)); buttonAdd = new JButton("+"); buttonAdd.setForeground(new Color(255, 0, 0)); buttonSub = new JButton("-"); buttonSub.setForeground(new Color(255, 0, 0)); buttonMul = new JButton("*"); buttonMul.setForeground(new Color(255, 0, 0)); buttonDiv = new JButton("/"); buttonDiv.setForeground(new Color(255, 0, 0)); buttonMod = new JButton("%"); buttonMod.setForeground(new Color(0, 0, 255)); buttonSqrt = new JButton("sqrt"); buttonSqrt.setForeground(new Color(0, 0, 255)); buttonDao = new JButton("1/x"); buttonDao.setForeground(new Color(0, 0, 255)); buttonEqual = new JButton("="); buttonEqual.setForeground(new Color(255, 0, 0)); //将所有行为与监听绑定 panel3.setLayout(new GridLayout(4, 6)); panel3.add(buttonMC); buttonMC.addActionListener(this); panel3.add(button[7]); button[7].addActionListener(this); panel3.add(button[8]); button[8].addActionListener(this); panel3.add(button[9]); button[9].addActionListener(this); panel3.add(buttonDiv); buttonDiv.addActionListener(this); panel3.add(buttonSqrt); buttonSqrt.addActionListener(this); panel3.add(buttonMR); buttonMR.addActionListener(this); panel3.add(button[4]); button[4].addActionListener(this); panel3.add(button[5]); button[5].addActionListener(this); panel3.add(button[6]); button[6].addActionListener(this); panel3.add(buttonMul); buttonMul.addActionListener(this); panel3.add(buttonMod); buttonMod.addActionListener(this); panel3.add(buttonMS); buttonMS.addActionListener(this); panel3.add(button[1]); button[1].addActionListener(this); panel3.add(button[2]); button[2].addActionListener(this); panel3.add(button[3]); button[3].addActionListener(this); panel3.add(buttonSub); buttonSub.addActionListener(this); panel3.add(buttonDao); buttonDao.addActionListener(this); panel3.add(buttonMAdd); buttonMAdd.addActionListener(this); panel3.add(button[0]); button[0].addActionListener(this); panel3.add(buttonAddAndSub); buttonAddAndSub.addActionListener(this); panel3.add(buttonDot); buttonDot.addActionListener(this); panel3.add(buttonAdd); buttonAdd.addActionListener(this); panel3.add(buttonEqual); buttonEqual.addActionListener(this); frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE); frame.pack(); frame.show(); } //设置各个按钮行为 public void actionPerformed(ActionEvent event) { boolean sign = false; //判断是否是double型数参与运算，是为true，不是为false Object temp = event.getSource(); try { //如果按下数据按钮，将按下的按钮代表的数据插入的当前文本框字符串之后 for (int i = 0; i <= 9; i++) if (temp == button[i] && clickable == true) textAnswer.setText(textAnswer.getText() + Integer.toString(i)); //按下'.'按钮时，判断当前文本框内字符串中含不含'.'，如果已含，则不允许再插入'.' if (temp == buttonDot && clickable == true) { boolean isDot = false; if (textAnswer.getText().length() == 0) isDot = true; for (int i = 0; i < textAnswer.getText().length(); i++) if ('.'