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關(guān)于科學(xué)型Java計(jì)數(shù)器的知識(shí)
科學(xué)型Java計(jì)數(shù)器：
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- 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 //導(dǎo)入動(dòng)作監(jiān)聽接口
設(shè)計(jì)面板中的單位：
- JFrame frame;
- JTextField textAnswer;
- JPanel panel, panel1, panel2, panel3;
- JMenuBar mainMenu;
- JTextField textMemory;
- JLabel labelMemSpace; //labelMemSpace單純做擺設(shè)，控制面板的外形
- 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; //設(shè)置數(shù)據(jù)輸出精度
- boolean clickable; //控制當(dāng)前能否按鍵
- double memoryd; //使用內(nèi)存中存儲(chǔ)的數(shù)字
- int memoryi;
- double vard, answerd; //用來保存double型數(shù)據(jù)的中間值(vard)和最后結(jié)果(answerd)
- short key = -1, prekey = -1; //key用來保存當(dāng)前進(jìn)行何種運(yùn)算,prekey用來保存前次進(jìn)行何種運(yùn)算
- String copy; //做復(fù)制用
- JTextArea help; //幫助
- JScrollPane scrollHelp;
構(gòu)造函數(shù)：
- public Calculator() {
- clickable = true;
- answerd = 0;
- frame = new JFrame("計(jì)算器");
- df = new DecimalFormat("0.##############"); //設(shè)置數(shù)據(jù)輸出精度(對(duì)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());
設(shè)計(jì)整個(gè)面板：
- mainMenu = new JMenuBar();
- editMenu = new JMenu("編輯(E)");
- viewMenu = new JMenu("查看(V)");
- helpMenu = new JMenu("幫助(H)");
- copyItem = new JMenuItem(" 復(fù)制(C) Ctrl+C");
- copyItem.addActionListener(this);
- pasteItem = new JMenuItem(" 粘貼(V) Ctrl+V");
- pasteItem.addActionListener(this);
- editMenu.add(copyItem);
- editMenu.add(pasteItem);
- tItem = new JMenuItem("●標(biāo)準(zhǔn)型(T)");
- tItem.addActionListener(this);
- sItem = new JMenuItem(" 科學(xué)型(S)");
- sItem.addActionListener(this);
- numberGroup = new JMenuItem(" 數(shù)字分組(I)");
- numberGroup.addActionListener(this);
- viewMenu.add(tItem);
- viewMenu.add(sItem);
- viewMenu.add(numberGroup);
- topHelp = new JMenuItem(" 幫助主題(H)");
- topHelp.addActionListener(this);
- help = new JTextArea(5, 20);
- scrollHelp = new JScrollPane(help);
- help.setEditable(false);
- help.append("執(zhí)行簡(jiǎn)單計(jì)算 ");
- help.append("1. 鍵入計(jì)算的第一個(gè)數(shù)字。 ");
- help.append("2. 單擊“+”執(zhí)行加、“-”執(zhí)行減、“*”執(zhí)行乘或“/”執(zhí)行除。 ");
- help.append("3. 鍵入計(jì)算的下一個(gè)數(shù)字。 ");
- help.append("4. 輸入所有剩余的運(yùn)算符和數(shù)字。 ");
- help.append("5. 單擊“=”。 ");
- aboutCal = new JMenuItem(" 關(guān)于計(jì)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));
將所有行為與監(jiān)聽綁定：
- 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();
- }
設(shè)置各個(gè)按鈕行為：
- public void actionPerformed(ActionEvent event) {
- boolean sign = false; //判定是否是double型數(shù)參與運(yùn)算，是為true，不是為false
- Object temp = event.getSource();
- try {
- //假如按下數(shù)據(jù)按鈕，將按下的按鈕代表的數(shù)據(jù)插入的當(dāng)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′.′按鈕時(shí)，判定當(dāng)前文本框內(nèi)字符串中含不含′.′，假如已含，則不答應(yīng)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("除數(shù)不能為零");
- 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());
- 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("除數(shù)不能為零");
- 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());
- 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("除數(shù)不能為零");
- clickable = false;
- }
- else
- answerd /= Double.parseDouble(textAnswer.getText());
- break;
- default:
- answerd = Double.parseDouble(textAnswer.getText());
- }
- textAnswer.setText("");
- prekey = key = 2;
- }
- //′/′操作
- if (temp == buttonDiv) {
- 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("除數(shù)不能為零");
- clickable = false;
- }
- else
- answerd /= Double.parseDouble(textAnswer.getText());
- break;
- default:
- answerd = Double.parseDouble(textAnswer.getText());
- }
- textAnswer.setText("");
- prekey = key = 3;
- }
- }
- //′=′操作
- if (temp == buttonEqual && clickable == true) {
- //假如連續(xù)按′=′,則進(jìn)行連續(xù)運(yùn)算
- if (prekey == 5) {
- if (key == 0) {
- answerd += vard;
- textAnswer.setText(df.format(answerd));
- }
- if (key == 1) {
- answerd -= vard;
- textAnswer.setText(df.format(answerd));
- }
- if (key == 2) {
- answerd *= vard;
- textAnswer.setText(df.format(answerd));
- }
- if (key == 3) {
- if (Double.parseDouble(textAnswer.getText()) == 0) {
- textAnswer.setText("除數(shù)不能為零");
- clickable = false;
- }
- else {
- answerd /= vard;
- textAnswer.setText(df.format(answerd));
- }
- }
- }
- else {
- vard = Double.parseDouble(textAnswer.getText());
- if (key == 0) {
- prekey = -1;
- answerd += Double.parseDouble(textAnswer.getText());
- textAnswer.setText(df.format(answerd));
- }
- if (key == 1) {
- prekey = -1;
- answerd -= Double.parseDouble(textAnswer.getText());
- textAnswer.setText(df.format(answerd));
- }
- if (key == 2) {
- prekey = -1;
- answerd *= Double.parseDouble(textAnswer.getText());
- textAnswer.setText(df.format(answerd));
- }
- if (key == 3) {
- prekey = -1;
- if (Double.parseDouble(textAnswer.getText()) == 0) {
- textAnswer.setText("除數(shù)不能為零");
- clickable = false;
- }
- else {
- answerd /= Double.parseDouble(textAnswer.getText());
- textAnswer.setText(df.format(answerd));
- }
- }
- }
- prekey = 5;
- }
- //′%′操作，對(duì)第二個(gè)操作數(shù)除以100
- if (temp == buttonMod && clickable == true) {
- if (answerd == 0) {
- String s = textAnswer.getText();
- textAnswer.setText(s);
- }
- else {
- boolean isDot = false;
- for (int i = 0; i < textAnswer.getText().length(); i++)
- if (′.′ == textAnswer.getText().charAt(i)) {
- isDot = true;
- break;
- }
- //假如是double數(shù)，除100
- if (isDot == true) {
- double dtemp = Double.parseDouble(textAnswer.getText());
- dtemp = dtemp / 100.0;
- textAnswer.setText(Double.toString(dtemp));
- }
- else {
- //假如是int數(shù)但能被100整除，則去掉末尾兩個(gè)零
- if (Integer.parseInt(textAnswer.getText()) % 100 == 0) {
- int itemp = Integer.parseInt(textAnswer.getText());
- itemp /= 100;
- textAnswer.setText(Integer.toString(itemp));
- }
- //假如是int數(shù)，但不能被100整除，則按double數(shù)處理
- else {
- double dtemp = Double.parseDouble(textAnswer.getText());
- dtemp = dtemp / 100.0;
- textAnswer.setText(Double.toString(dtemp));
- }
- }
- }
- }
- //開根號(hào)運(yùn)算
- if (temp == buttonSqrt && clickable == true) {
- String s = textAnswer.getText();
- if (s.charAt(0) == ′-′) {
- textAnswer.setText("負(fù)數(shù)不能開根號(hào)");
- clickable = false;
- }
- else
- textAnswer.setText(Double.toString(java.lang.Math.sqrt(Double.
- parseDouble(textAnswer.getText()))));
- }
- //倒數(shù)運(yùn)算
- if (temp == buttonDao && clickable == true) {
- if (textAnswer.getText().charAt(0) == ′0′ &&
- textAnswer.getText().length() == 1) {
- textAnswer.setText("零不能求倒數(shù)");
- clickable = false;
- }
- else {
- boolean isDec = true;
- int i, j, k;
- String s = Double.toString(1 / Double.parseDouble(textAnswer.getText()));
- for (i = 0; i < s.length(); i++)
- if (s.charAt(i) == ′.′)
- break;
- for (j = i + 1; j < s.length(); j++)
- if (s.charAt(j) != ′0′) {
- isDec = false;
- break;
- }
- if (isDec == true) {
- String stemp = "";
- for (k = 0; k < i; k++)
- stemp += s.charAt(k);
- textAnswer.setText(stemp);
- }
- else
- textAnswer.setText(s);
- }
- }
- //按下′+/-′按鈕時(shí)處理
- if (temp == buttonAddAndSub && clickable == true) {
- boolean isNumber = true;
- String s = textAnswer.getText();
- for (int i = 0; i < s.length(); i++)
- if (! (s.charAt(i) >= ′0′ && s.charAt(i) <= ′9′ s.charAt(i) == ′.′
- s.charAt(i) == ′-′)) {
- isNumber = false;
- break;
- }
- if (isNumber == true) {
- //假如當(dāng)前字符串首字母有′-′號(hào),代表現(xiàn)在是個(gè)負(fù)數(shù),再按下時(shí),則將首符號(hào)去掉
- if (s.charAt(0) == ′-′) {
- textAnswer.setText("");
- for (int i = 1; i < s.length(); i++) {
- char a = s.charAt(i);
- textAnswer.setText(textAnswer.getText() + a);
- }
- }
- //假如當(dāng)前字符串第一個(gè)字符不是符號(hào)，則添加一個(gè)符號(hào)在首字母處
- else
- textAnswer.setText(′-′ + s);
- }
- }
- //計(jì)算器有關(guān)內(nèi)存操作
- //′MC′的操作，將內(nèi)存清0
- if (temp == buttonMC && clickable == true) {
- memoryd = memoryi = 0;
- textMemory.setText("");
- }
- //′MS′的操作，將當(dāng)前文本框內(nèi)容保存入內(nèi)存，顯示′M′
- if (temp == buttonMS && clickable == true) {
- boolean isDot = false;
- textMemory.setText(" M");
- for (int i = 0; i < textAnswer.getText().length(); i++)
- if (′.′ == textAnswer.getText().charAt(i)) {
- isDot = true;
- break;
- }
- //假如是double,則存入memoryd(double存儲(chǔ)器)
- if (isDot == true) {
- memoryd = Double.parseDouble(textAnswer.getText());
- memoryi = 0; //保證存儲(chǔ)器中存放最新的值
- }
- //假如是int,則存入memoryi(int存儲(chǔ)器)
- else {
- memoryi = Integer.parseInt(textAnswer.getText());
- memoryd = 0; //保證存儲(chǔ)器中存放最新的值
- }
- }
- //′MR′的操作，將存儲(chǔ)器中的信息輸出
- if (temp == buttonMR && clickable == true) {
- if (memoryd != 0)
- textAnswer.setText(Double.toString(memoryd));
- if (memoryi != 0)
- textAnswer.setText(Integer.toString(memoryi));
- }
- //′M+′的功能，將當(dāng)前文本框里的數(shù)據(jù)和存儲(chǔ)器中數(shù)據(jù)相加后，再存入存儲(chǔ)器
- if (temp == buttonMAdd && clickable == true) {
- boolean isDot = false; 分享名稱：關(guān)于科學(xué)型Java計(jì)數(shù)器的知識(shí)
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