calculator.java

带液晶显示的计算器

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.text.DecimalFormat;
import java.awt.image.BufferedImage;
public class Calculator implements ActionListener
{
    JFrame        frame;
    JPanel        panel,
    panel1,
    panel2,
    panel3,
    panel4;
    DPanel        display;
    JMenuBar      mainMenu;
    JTextField    textMemory;
    JButton       buttonBk,
    buttonCe,
    buttonC;
    JButton       button [];
    JButton       buttonMC,
    buttonMR,
    buttonMS,
    buttonMAdd;
    JButton       buttonDot,
    buttonAddAndSub,
    buttonAdd,
    buttonSub,
    buttonMul,
    buttonDiv,
    buttonMod;
    JButton       buttonSqrt,
    buttonDao,
    buttonEqual;
    JMenu         fileMenu,
    editMenu,
    viewMenu,
    helpMenu;
    JMenuItem     exitItem,
    copyItem,
    pasteItem,
    tItem,
    sItem,
    topHelp,
    aboutCal;
    DecimalFormat df;
    boolean       clickable;
    boolean       clear = false; //判断是否要清除之前的运算结果，要是为true,不要为false
    double        memoryd=0;
    int           memoryi=0;
    double        vard,
    answerd;
    short         key = -1,
    prekey = -1;
    String        copy;
    JTextArea     help;
    JScrollPane   scrollHelp;
    String        textResult = "0";
    public Calculator()
    {
        clickable = true;
        answerd = 0;
        JFrame.setDefaultLookAndFeelDecorated(true);
        JDialog.setDefaultLookAndFeelDecorated(true);
        frame = new JFrame("计算器");
        df = new DecimalFormat("0.#######");
        panel = new JPanel();
        panel1 = new JPanel();
        panel2 = new JPanel();
        panel3 = new JPanel();
        panel4 = new JPanel();
        display = new DPanel();
        frame.getContentPane().add(panel);
        panel.setLayout(new BorderLayout());
        panel1.setLayout(new BorderLayout());
        panel2.setLayout(new FlowLayout(FlowLayout.RIGHT));
        panel3.setLayout(new GridLayout(4, 6));
        panel4.setLayout(new BorderLayout());
        mainMenu = new JMenuBar();
        fileMenu = new JMenu("文件(F)");
        editMenu = new JMenu("编辑(E)");
        viewMenu = new JMenu("查看(V)");
        helpMenu = new JMenu("帮助(H)");
        exitItem = new JMenuItem("退出(Q)");
        exitItem.addActionListener(this);
        fileMenu.add(exitItem);
        copyItem = new JMenuItem("复制(C)");
        copyItem.addActionListener(this);
        pasteItem = new JMenuItem("粘贴(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);
        viewMenu.add(tItem);
        viewMenu.add(sItem);
        topHelp = new JMenuItem("帮助主题(H)");
        topHelp.addActionListener(this);
        help = new JTextArea(6, 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(fileMenu);
        mainMenu.add(editMenu);
        mainMenu.add(viewMenu);
        mainMenu.add(helpMenu);
        panel.add(mainMenu, BorderLayout.NORTH);
        panel.add(panel4, BorderLayout.CENTER);
        panel.add(panel1, BorderLayout.SOUTH);
        textMemory = new JTextField(3);
        textMemory.setEditable(false);
        textMemory.setBackground(new Color(217, 217, 217));
        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);
        panel1.add(panel3, BorderLayout.CENTER);
        panel2.add(textMemory);
        panel2.add(buttonBk);
        panel2.add(buttonCe);
        panel2.add(buttonC);
        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("√￣");
        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));
        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);
        panel4.add(display, BorderLayout.CENTER);
        frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
        frame.setSize(400, 320);
        frame.show();
    }
    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)
            {
                if(clear)textResult="";
                if(textResult.equals("0"))textResult = "";
                textResult = textResult + Integer.toString(i);
                display.str = textResult;
                clear=false;
            }
            //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 (textResult.length() == 0)
                isDot = true;
                for (int i = 0; i < textResult.length(); i++)
                if ('.' == textResult.charAt(i))
                {
                    isDot = true;
                    break;
                }
                if (isDot == false)
                {
                    textResult = textResult + ".";
                    display.str = textResult;
                }
            }
            if ((temp == buttonAdd || temp == buttonSub || temp == buttonMul || temp == buttonDiv) && clickable == true)
            {
                //'+'操作
                if (temp == buttonAdd)
                {
                    switch (prekey)
                    {
                    case 0:
                        answerd += Double.parseDouble(textResult);
                        break;
                    case 1:
                        answerd -= Double.parseDouble(textResult);
                        break;
                    case 2:
                        answerd *= Double.parseDouble(textResult);
                        break;
                    case 3:
                        if (Double.parseDouble(textResult) == 0)
                        {
                            textResult="E";
                            clickable = false;
                        }
                        else
                        answerd /= Double.parseDouble(textResult);
                        break;
                    default:
                        answerd = Double.parseDouble(textResult);
                    }
                    textResult = "";
                    prekey = key = 0;
                }
                //'-'操作
                if (temp == buttonSub)
                {
                    switch (prekey)
                    {
                    case 0:
                        answerd += Double.parseDouble(textResult);
                        break;
                    case 1:
                        answerd -= Double.parseDouble(textResult);
                        break;
                    case 2:
                        answerd *= Double.parseDouble(textResult);
                        break;
                    case 3:
                        if (Double.parseDouble(textResult) == 0)
                        {
                            textResult="E";
                            clickable = false;
                        }
                        else
                        answerd /= Double.parseDouble(textResult);
                        break;
                    default:
                        answerd = Double.parseDouble(textResult);
                    }
                    textResult = "";
                    prekey = key = 1;
                }
                //'*'操作
                if (temp == buttonMul)
                {
                    switch (prekey)
                    {
                    case 0:
                        answerd += Double.parseDouble(textResult);