calculator.java

这是用java写的一个简单的计算器源码

//frame版程序源代码如下，疏漏之处，望批评指正。 
//数字分组没有编写，科学型计算器没有编写，其他已经完善。 
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 { 
    JFrame frame; 
    JTextField textAnswer; 
    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 editMenu, viewMenu, helpMenu; 
    JMenuItem copyItem, pasteItem, tItem, sItem, numberGroup, 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.##############"); //设置数据输出精度(对于double型值) 
        textAnswer = new JTextField(15); 
        textAnswer.setText(""); 
        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(); 
        editMenu = new JMenu("编辑(E)"); 
        viewMenu = new JMenu("查看(V)"); 
        helpMenu = new JMenu("帮助(H)"); 
        copyItem = new JMenuItem(" 复制(C) Ctrl+C"); 
        copyItem.addActionListener(this); 
        pasteItem = new JMenuItem(" 粘贴(V) Ctrl+V"); 
        pasteItem.addActionListener(this); 
        editMenu.add(copyItem); 
        editMenu.add(pasteItem); 
        tItem = new JMenuItem("●标准型(T)"); 
        tItem.addActionListener(this); 
        sItem = new JMenuItem(" 科学型(S)"); 
        sItem.addActionListener(this); 
        numberGroup = new JMenuItem(" 数字分组(I)"); 
        numberGroup.addActionListener(this); 
        viewMenu.add(tItem); 
        viewMenu.add(sItem); 
        viewMenu.add(numberGroup); 
        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(editMenu); 
        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 ('.' == textAnswer.getText().charAt(i)) { 
                          isDot = true; 
                          break; 
                     } 
                     if (isDot == false) 
                         textAnswer.setText(textAnswer.getText() + "."); 
           } 
           if ( (temp == buttonAdd || temp == buttonSub || temp == buttonMul || 
           temp == buttonDiv) && clickable == true) { 
           //'+'操作 
      if (temp == buttonAdd) { 
            switch (prekey) { 
               case 0: 
                   answerd += Double.parseDouble(textAnswer.getText()); 
                   break; 
               case 1: 
                   answerd -= Double.parseDouble(textAnswer.getText()); 
                   break; 
               case 2: 
                   answerd *= Double.parseDouble(textAnswer.getText()); 
                   break; 
               case 3: 
                   if (Double.parseDouble(textAnswer.getText()) == 0) { 
                       textAnswer.setText("除数不能为零"); 
                       clickable = false; 
                   } 
                   else 
                       answerd /= Double.parseDouble(textAnswer.getText()); 
                       break; 
              default: 
                       answerd = Double.parseDouble(textAnswer.getText()); 
           } 
           textAnswer.setText(""); 
           prekey = key = 0; 
     } 
//'-'操作 
     if (temp == buttonSub) { 
           switch (prekey) { 
              case 0: 
                  answerd += Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(Double.toString(answerd)));
                  break; 
              case 1: 
                  answerd -= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(Double.toString(answerd)));
                  break; 
              case 2: 
                  answerd *= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(Double.toString(answerd)));
                  break; 
              case 3: 
                  if (Double.parseDouble(textAnswer.getText()) == 0) { 
                       textAnswer.setText("除数不能为零"); 
                       clickable = false; 
                  } 
                  else 
                       answerd /= Double.parseDouble(textAnswer.getText()); 
                  break; 
             default: 
                  answerd = Double.parseDouble(textAnswer.getText()); 
         } 
         textAnswer.setText(""); 
         prekey = key = 1; 
     } 
//'*'操作 
     if (temp == buttonMul) { 
          switch (prekey) { 
              case 0: 
                  answerd += Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(Double.toString(answerd)));
                  break; 
              case 1: 
                  answerd -= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(Double.toString(answerd)));
                  break; 
              case 2: 
                  answerd *= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(Double.toString(answerd)));
                  break; 
              case 3: 
                  if (Double.parseDouble(textAnswer.getText()) == 0) { 
                       textAnswer.setText("除数不能为零"); 
                       clickable = false; 
                  } 
                  else 
                       answerd /= Double.parseDouble(textAnswer.getText()); 
                  break; 
             default: 
                  answerd = Double.parseDouble(textAnswer.getText()); 
          } 
          textAnswer.setText("");