Java---计算器（标准计算器，科学计算器）的实现

Java-计算器（标准计算器和科学计算器）的实现 / 需要说明这里的文本框中并不能呈现出算数表达式，有时间改进 可以先建两个类，一个是Biaozhun 用来实现标准计算器，另一个是Kexue 用来实现科学计算器

通过功能菜单实现科学计算器和标准计算器的转换 具体代码中，在Biaozhun类 和 Kexue类 各自定义相对应的事件来实现转换

menuItem_1.addActionListener(new ActionListener() menuItem.addActionListener(new ActionListener()

对于每一个按钮也要设置相应的事件响应（详情见代码）

代码部分

首先是标准计算器的实现

package dazuoye; import java.awt.*; import java.awt.event.*; import javax.swing.*; @SuppressWarnings("serial") public class Biaozhun extends JFrame implements ActionListener { private final String[] KEYS = { "*", "/", "7", "8", "9","+", "4", "5", "6", "-", "1", "2", "3", "|x|","0",".","=", "1/x" }; private final String[] COMMAND = { "Back", "C" }; private JButton keys[] = new JButton[KEYS.length]; private JButton commands[] = new JButton[COMMAND.length]; private JTextField resultText = new JTextField("0"); private boolean firstDigit = true; private double resultNum = 0.0; private String operator = "="; private boolean operateValidFlag = true; StringBuffer sb = new StringBuffer(); String vl = null; public Biaozhun() { setTitle("标准型"); this.setBackground(Color.LIGHT_GRAY); this.setTitle("标准计算器"); this.setLocation(500, 300); this.setSize(500, 500); this.setResizable(false); JMenuBar menuBar = new JMenuBar(); setJMenuBar(menuBar); JMenu menu = new JMenu("功能"); menuBar.add(menu); JMenuItem menuItem = new JMenuItem("标准型"); menu.add(menuItem); JMenuItem menuItem_1 = new JMenuItem("科学型"); menu.add(menuItem_1); menuItem_1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent arg0) { Kexue science = new Kexue(); science.setVisible(true); } } ); resultText.setHorizontalAlignment(JTextField.RIGHT); resultText.setBackground(Color.white); resultText.setFont(new Font("TimesRoman",Font.BOLD,46)); JPanel PPanel = new JPanel(); PPanel.setLayout(new GridLayout(5, 4, 3, 3)); for (int i = 0; i < COMMAND.length; i++) { commands[i] = new JButton(COMMAND[i]); PPanel.add(commands[i]); commands[i].setFont(new Font("Courir",Font.PLAIN,20)); } for (int i = 0; i < KEYS.length; i++) { keys[i] = new JButton(KEYS[i]); PPanel.add(keys[i]); keys[i].setFont(new Font("Courir",Font.ITALIC,20)); } JPanel panel1 = new JPanel(); panel1.setLayout(new BorderLayout(3,3)); panel1.add("Center", PPanel); JPanel top = new JPanel(); top.setLayout(new BorderLayout()); top.add("Center", resultText); getContentPane().setLayout(new BorderLayout(3, 5)); getContentPane().add("North", top); getContentPane().add("Center", panel1); for (int i = 0; i < KEYS.length; i++) { keys[i].addActionListener(this); } for (int i = 0; i < COMMAND.length; i++) { commands[i].addActionListener(this); } } public void actionPerformed(ActionEvent e) { String label = e.getActionCommand(); if (label.equals(COMMAND[0])) { handleBack(); } else if (label.equals(COMMAND[1])) { handleC(); } else if ("0123456789.".indexOf(label) >= 0) { handleNumber(label); } else handleOperator(label); } private void handleBack() { String text = resultText.getText(); int i = text.length(); if (i > 0) { text = text.substring(0, i - 1); if (text.length() == 0) { resultText.setText("0"); firstDigit = true; operator = "="; } else resultText.setText(text); } } private void handleNumber(String key) { if (firstDigit) { resultText.setText(key); } else if ((key.equals(".")) && (resultText.getText().indexOf(".") < 0)) { resultText.setText(resultText.getText() + "."); } else if (!key.equals(".")) { resultText.setText(resultText.getText() + key); } firstDigit = false; } private void handleC() { resultText.setText("0"); firstDigit = true; operator = "="; } private void handleOperator(String key) { if (operator.equals("/")) { if (getNumberFromText() == 0.0) { operateValidFlag = false; resultText.setText("除数不能为零"); } else resultNum /= getNumberFromText(); } else if (operator.equals("1/x")) { if (resultNum == 0.0) { operateValidFlag = false; resultText.setText("零没有倒数"); } else resultNum = 1 / resultNum; } else if (operator.equals("+")) { resultNum += getNumberFromText(); } else if (operator.equals("-")) { resultNum -= getNumberFromText(); } else if (operator.equals("*")) { resultNum *= getNumberFromText(); } else if (operator.equals("|x|")) { resultNum = Math.abs(resultNum); } else if (operator.equals("=")) { resultNum = getNumberFromText(); } if (operateValidFlag) { long t1; double t2; t1 = (long) resultNum; t2 = resultNum - t1; if (t2 == 0) { resultText.setText(String.valueOf(t1)); } else { resultText.setText(String.valueOf(resultNum)); } } operator = key; firstDigit = true; operateValidFlag = true; } private double getNumberFromText() { double result = 0; try { result = Double.valueOf(resultText.getText()).doubleValue(); } catch (NumberFormatException e) {} return result; } public static void main(String args[]) { Biaozhun application = new Biaozhun(); application.setVisible(true); application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } }

接着是科学计算器的实现

package dazuoye; import java.awt.*; import java.awt.event.*; import javax.swing.*; @SuppressWarnings("serial") public class Kexue extends JFrame implements ActionListener { private final String[] KEYS = { "*", "/", "7", "8", "9","+", "4", "5", "6", "-", "1", "2", "3", "|x|","0",".","=", "1/x" }; private final String[] COMMAND = { "Back", "C" }; private JButton keys[] = new JButton[KEYS.length]; private JButton commands[] = new JButton[COMMAND.length]; private JTextField resultText = new JTextField("0"); private boolean firstDigit = true; private double resultNum = 0.0; private String operator = "="; private boolean operateValidFlag = true; private final String[] KEYS2= {"X^2","X^3","X^Y","Sqrt","rt","X!","ln","lg","%","sin","cos","tan","PI","e","e^X"}; private JButton keys2[]=new JButton[KEYS2.length]; StringBuffer sb = new StringBuffer(); String vl = null; private JPanel contentPane,contentpane2; private FlowLayout layout; public Kexue() { super("科学型"); this.setBackground(Color.LIGHT_GRAY); this.setTitle("科学计算器"); this.setSize(800, 500); JMenuBar menuBar = new JMenuBar(); setJMenuBar(menuBar); JMenu menu = new JMenu("功能"); menuBar.add(menu); JMenuItem menuItem = new JMenuItem("标准型"); menu.add(menuItem); JMenuItem menuItem_1 = new JMenuItem("科学型"); menu.add(menuItem_1); menuItem.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { Biaozhun ordinary = new Biaozhun(); ordinary.setVisible(true); } } ); resultText.setHorizontalAlignment(JTextField.RIGHT); resultText.setBackground(Color.white); resultText.setFont(new Font("TimesRoman",Font.BOLD,46)); JPanel PPanel=new JPanel(); PPanel.setLayout(new GridLayout(5, 4, 3, 3)); for (int i = 0; i < COMMAND.length; i++) { commands[i] = new JButton(COMMAND[i]); PPanel.add(commands[i]); commands[i].setFont(new Font("Courir",Font.PLAIN,20)); } for (int i = 0; i < KEYS.length; i++) { keys[i] = new JButton(KEYS[i]); PPanel.add(keys[i]); keys[i].setFont(new Font("Courir",Font.ITALIC,20)); } JPanel panel1 = new JPanel(); panel1.setLayout(new BorderLayout(3,3)); panel1.add("Center", PPanel); JPanel top = new JPanel(); top.setLayout(new BorderLayout()); top.add("Center", resultText); contentPane=new JPanel(); contentPane.setLayout(new BorderLayout(3, 5)); contentPane.add("North", top); contentPane.add("Center", panel1); //second JPanel ppanel=new JPanel(); ppanel.setLayout(new GridLayout(5, 3, 3, 3)); for (int i = 0; i < KEYS2.length; i++) { keys2[i] = new JButton(KEYS2[i]); ppanel.add(keys2[i]); keys2[i].setFont(new Font("Courir",Font.ITALIC,20)); } contentpane2 = new JPanel(); contentpane2.setLayout(new BorderLayout(3, 5)); contentpane2.add("Center", ppanel); layout=new FlowLayout(); JPanel ane= new JPanel(); ane.setLayout(layout); getContentPane().setLayout(new BorderLayout(3,5)); getContentPane().add("Center", contentPane); getContentPane().add("East", contentpane2); //event for (int i = 0; i < KEYS.length; i++) { keys[i].addActionListener(this); } for (int i = 0; i < COMMAND.length; i++) { commands[i].addActionListener(this); } for (int i = 0; i < KEYS2.length; i++) keys2[i].addActionListener(this); setVisible(true); } //make it public void actionPerformed(ActionEvent e) { String label = e.getActionCommand(); if (label.equals(COMMAND[0])) { handleBack(); } else if (label.equals(COMMAND[1])) { handleC(); } else if ("0123456789.".indexOf(label) >= 0) { handleNumber(label); } else if(label.equals("PI")) resultText.setText(String.valueOf(3.14159265)); else if(label.equals("e")) resultText.setText(String.valueOf(2.17828)); else handleOperator(label); } // private void handleBack() { String text = resultText.getText(); int i = text.length(); if (i > 0) { text = text.substring(0, i - 1); if (text.length() == 0) { resultText.setText("0"); firstDigit = true; operator = "="; } else resultText.setText(text); } } private void handleNumber(String key) { if (firstDigit) { resultText.setText(key); } else if ((key.equals(".")) && (resultText.getText().indexOf(".") < 0)) { resultText.setText(resultText.getText() + "."); } else if (!key.equals(".")) { resultText.setText(resultText.getText() + key); } firstDigit = false; } private void handleC() { resultText.setText("0"); firstDigit = true; operator = "="; } private void handleOperator(String key) { if (operator.equals("/")) { if (getNumberFromText() == 0.0) { operateValidFlag = false; resultText.setText("除数不能为零"); } else resultNum /= getNumberFromText(); } else if (operator.equals("1/x")) { if (resultNum == 0.0) { operateValidFlag = false; resultText.setText("零没有倒数"); } else resultNum = 1 / resultNum; } else if (operator.equals("+")) { resultNum += getNumberFromText(); } else if (operator.equals("-")) { resultNum -= getNumberFromText(); } else if (operator.equals("*")) { resultNum *= getNumberFromText(); } else if (operator.equals("|x|")) { resultNum = Math.abs(resultNum); } else if (operator.equals("X^2")) { resultNum = resultNum*resultNum; } else if (operator.equals("X^3")) { resultNum = resultNum*resultNum*resultNum; } else if (operator.equals("X^Y")) { resultNum = Math.pow(resultNum,getNumberFromText()); } else if (operator.equals("Sqrt")) { resultNum = Math.sqrt(resultNum); } else if (operator.equals("rt")) { resultNum = resultNum*57.3; } else if (operator.equals("X!")) { int ee; double re=resultNum ; int c=1; for(ee=1;ee<=re;ee++) { c=c*ee; resultNum=c;} } else if (operator.equals("ln")) { resultNum = Math.log(resultNum); } else if (operator.equals("lg")) { resultNum = Math.log10(resultNum); } else if (operator.equals("%")) { resultNum %= getNumberFromText(); }else if (operator.equals("sin")) { resultNum = Math.sin(resultNum); } else if (operator.equals("cos")) { resultNum = Math.cos(resultNum); } else if (operator.equals("tan")) { resultNum = Math.tan(resultNum); } else if (operator.equals("e^X")) { resultNum = Math.exp(resultNum); } else if (operator.equals("=")) { resultNum = getNumberFromText(); } if (operateValidFlag) { long t1; double t2; t1 = (long) resultNum; t2 = resultNum - t1; if (t2 == 0) { resultText.setText(String.valueOf(t1)); } else { resultText.setText(String.valueOf(resultNum)); } } operator = key; firstDigit = true; operateValidFlag = true; } private double getNumberFromText() { double result = 0; try { result = Double.valueOf(resultText.getText()).doubleValue(); } catch (NumberFormatException e) {} return result; } public static void main(String args[]) { EventQueue.invokeLater(new Runnable() { public void run() { try { Kexue application = new Kexue(); application.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } } ); } }

运行结果

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结束

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