src/Calculator.java

@@ -0,0 +1,315 @@
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.text.DecimalFormat;
+import java.math.BigInteger;
+//时间允许，可通过引入一下包，实现鼠标滑过按钮变色和键盘输入
+//import java.awt.event.MouseAdapter;
+//import java.awt.event.MouseEvent;
+//import java.awt.event.KeyAdapter;
+//import java.awt.event.KeyEvent;
+import java.math.BigDecimal;//控制小数点后几位
+import java.awt.*
+;@SuppressWarnings("unused")
+public class Calculator implements ActionListener {
+
+    private JFrame frame = new JFrame();//界面应用程序，窗口
+
+    //计算器上各按键的符号
+    private String[] keys = {"%", "CE", "C", "←", "n!", "aⁿ", "cos", "sin", "1/x", "x²", "√x", "÷", "7", "8", "9",
+            "×", "4", "5", "6", "－", "1", "2", "3", "+", "+/-", "0", ".", "="};
+    private JButton button[] = new JButton[keys.length];  //计算器上按键的按钮（数组保存）
+    private JTextField resultText = new JTextField("0");//显示计算结果文本框
+    private JTextField processText = new JTextField();//显示计算过程文本框
+    private boolean firstDigit = true;  // 标志用户按的是否是整个表达式的第一个数字,或者是运算符后的第一个数字
+    private double resultNum = 0.0000;   // 计算的中间结果
+    private String operator = "=";   // 当前运算的运算符（按键"C"时需要将其还原为"="）
+    private boolean operateValidFlag = true;   // 判断操作是否合法
+
+    char charA;
+
+    public Calculator() {//本类Calculator的构造函数
+        init();  // 初始化计算器
+
+        frame.setTitle("计算器");
+        frame.setSize(350, 550);
+        frame.setLocation(500, 300);
+        frame.setResizable(true);  // 允许修改计算器窗口的大小
+        frame.setVisible(true);
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//点击关闭按钮后执行exit退出应用程序
+    }
+
+
+    private void init() {//初始化变量，创建面板，添加按钮，面板布局
+        Color color1 = new Color(181, 181, 181);
+        Color color2 = new Color(126, 192, 238);  //等于号专属颜色
+        Color color3 = new Color(232, 232, 232);  //背景颜色//功能键和运算符颜色
+        Color color4 = new Color(132, 132, 232);//紫色
+
+        JPanel resultTextPanel = new JPanel();// 建立一个画板放文本框
+        resultTextPanel.setLayout(new BorderLayout());
+        resultTextPanel.setSize(400, 50);
+        resultTextPanel.add(resultText);
+        resultText.setFont(new Font("黑体", Font.BOLD, 55));  //设置文本框中文字的字体以及大小，加粗
+        resultText.setHorizontalAlignment(JTextField.RIGHT);  //文本框中的内容采用右对齐方式
+        resultText.setEditable(false);  //不能修改结果文本框
+        resultText.setBorder(null);  //删除文本框的边框
+        resultText.setBackground(color1);// 设置文本框背景颜色
+
+        JPanel processTextPanel = new JPanel();
+        processTextPanel.setLayout(new BorderLayout());
+        processTextPanel.setSize(400, 50);
+        processTextPanel.add(processText);
+        processText.setFont(new Font("黑体", Font.PLAIN, 25));  //设置文本框中文字的字体以及大小，加粗
+        processText.setHorizontalAlignment(JTextField.RIGHT);  //文本框中的内容采用右对齐方式
+        processText.setEditable(false);  //不能修改结果文本框
+        processText.setBorder(null);  //删除文本框的边框
+
+        processText.setBackground(color1);
+
+        // 初始化计算器上键的按钮，将键放在一个画板内
+        JPanel keysPanel = new JPanel();
+        // 用网格布局器，6行，4列的网格，网格之间的水平方向垂直方向间隔均为2个像素
+        keysPanel.setLayout(new GridLayout(7, 4, 2, 2));
+
+        //初始化功能按钮
+        for (int i = 0; i < 12; i++) {
+            button[i] = new JButton(keys[i]);
+            Dimension preferredSize = new Dimension(95, 50);
+            button[i].setPreferredSize(preferredSize);
+            keysPanel.add(button[i]);
+            button[i].setBackground(color3);
+            button[i].setForeground(Color.black);//设置字体颜色
+            button[i].setFont(new Font(Font.SERIF, Font.PLAIN, 18));
+            if (i == 11 || i == 3) button[i].setFont(new Font(Font.SERIF, Font.PLAIN, 30));
+            if (i == 1 || i == 2) button[i].setFont(new Font("黑体", Font.PLAIN, 18));
+            button[i].setBorderPainted(false);  //去除按钮的边框
+        }
+
+        //初始化运算符及数字键按钮
+        for (int i = 12; i < keys.length; i++) {
+            button[i] = new JButton(keys[i]);
+            Dimension preferredSize = new Dimension(95, 50);
+            button[i].setPreferredSize(preferredSize);
+            keysPanel.add(button[i]);
+            if ((i + 1) % 4 == 0) {
+                button[i].setBackground(color3);//运算符按钮
+                button[i].setFont(new Font(Font.SERIF, Font.PLAIN, 30));
+            } else {
+                button[i].setBackground(Color.white);//数字按钮
+                button[i].setFont(new Font("黑体", Font.BOLD, 20));
+            }
+            if (i == 19) button[i].setFont(new Font(Font.SERIF, Font.PLAIN, 18));
+            button[i].setForeground(Color.black);
+
+            button[i].setBorderPainted(false);  //去除按钮的边框
+        }
+        button[27].setBackground(color4);  // 用紫色 覆盖更改 标记'='
+
+        keysPanel.setBackground(color1);
+
+        //将文本框所在的面板放在北部和中部，将keysPanel面板放在计算器的南部
+        frame.getContentPane().add("North", processTextPanel);
+        frame.getContentPane().add("Center", resultTextPanel);
+        frame.getContentPane().add("South", keysPanel);
+        processTextPanel.setBorder(BorderFactory.createMatteBorder(25, 3, 0, 3, color1));
+        resultTextPanel.setBorder(BorderFactory.createMatteBorder(0, 3, 5, 3, color1));
+        keysPanel.setBorder(BorderFactory.createMatteBorder(5, 3, 5, 3, color1));
+        
+        for (int i = 0; i < keys.length;i++){
+        	button[i].addActionListener(this);//为各按钮添加事件监听器，都使用同一个事件监听器
+        }
+    }
+    public void actionPerformed(ActionEvent ev){//监听函数，将得到的事件选择对应的函数
+    	String command = ev.getActionCommand();//获取事件源
+    	if (command.equals(keys[3])) doBackspace();//用户按了"Back"鍵键
+    	else if (command.equals(keys[1])) resultText.setText("0");//用户按了"CE"键
+    	else if (command.equals(keys[2])) doC();//用户按了"C"键
+    	else if ("0123456789.".indexOf(command)>= 0) doNumber(command);//用户按了数字键
+        else if (command.equals(keys[0])||command.equals(keys[4])||command.equals(keys[6])
+        		||command.equals(keys[7])|| command.equals(keys[8])||command.equals(keys[9])
+                ||command.equals(keys[10]) || command.equals(keys[24])) doOperator1(command);
+    		//用户按了只需一个数的运算键（求倒数，%，开方，平方，取正负数）
+    	else doOperator2(command); 
+}
+    private void doBackspace(){//删除鍵
+     	String text = resultText.getText();
+        int i = text.length();
+    	if (i > 0){
+    	text = text.substring(0, i - 1);//退格，将文本最后一个字符去掉
+    	if (text.length()== 0){
+    	resultText.setText("0");//如果文本没有内容了，则初始化计算器的各种值
+    	firstDigit = true;
+    	operator ="=";
+    	} else {
+    	resultText.setText(text);//显示新的文本
+    	}
+    }
+ }
+    
+    	
+    private void doC(){//清除鍵
+    	//初始化计算器的各种值
+    	processText.setText(null);
+    	resultText.setText("0");
+    	firstDigit = true;
+    	operator ="=";
+    }
+    	private void doNumber(String key){//得到数字，处理数字
+    	if (firstDigit){
+    	//输入的为第一个数
+    	resultText.setText(null);
+    	resultText.setText(key);
+    	} else if ((key.equals("."))&&(resultText.getText().indexOf(".")<0)){
+    	} else if ((key.equals("."))&&(resultText.getText().indexOf(".")< 0)){
+    		//index0f(）返回指定字符在字符串中第一次出现处的索引，如果此字符串中没有这样的字符,则返回-1
+    		//输入的是小数点，并且之前没有小数点，则将小数点附在结果文本框的后面
+    		resultText.setText(resultText.getText()+".");
+    		} else if (!key.equals(".")){//如果输入的不是小数点，则将数字附在结果文本框的后面
+    		resultText.setText(resultText.getText()+ key);
+    		}
+    	firstDigit=false;
+    }
+    	private void doOperator1(String key){//进行单目运算
+    		operator = key;//运算符为用户按的按钮
+    		if (operator.equals("1/x")){//倒数运算
+    		if (resultNum == 0){
+    		  operateValidFlag = false;//操作不合法
+    		  resultText.setText("除数不能为零");
+    		} else {
+    		  resultNum = 1 / getNumberFromText();
+    		  processText.setText("1/("+ resultText.getText()+")");
+    		} 
+    		}else if (operator.equals("√x")){//平方根运算
+    		  if (resultNum < 0){
+    		     operateValidFlag = false;//操作不合法
+    		     resultText.setText("无效输入");
+    		} else {
+    		resultNum = Math.sqrt(getNumberFromText());
+            processText.setText("√("+resultText.getText()+")");
+            //resultNum=getNumberFromText();
+    		}
+    	} else if (operator.equals("x²")){//平方运算X
+    		resultNum = getNumberFromText()* getNumberFromText();
+    		processText.setText("sqr("+ resultText.getText()+")");
+    		} else if (operator.equals("%")){//百分号运算，除以100
+    		resultNum = getNumberFromText()/ 100;
+    		} else if (operator.equals("n!")){
+    			BigInteger num = new BigInteger("1");
+    			BigInteger flat = new BigInteger("1");
+    			for (int i = 0; i < getNumberFromText(); i++){
+    			 flat = flat.multiply(num);
+    			 num = num.add(new BigInteger("1"));
+    			 }
+    			resultNum = flat.floatValue();//BigInteger转换为float
+    			processText.setText("fact("+ resultText.getText()+")");
+    		} else if (operator.equals("cos")){
+    			resultNum = Math.cos(getNumberFromText());
+    			processText.setText("cos("+ resultText.getText()+")");
+    		} else if (operator.equals("sin")){
+    			resultNum = Math.sin(getNumberFromText());
+    			processText.setText("sin("+ resultText.getText()+")");
+    		} else if (operator.equals("+/-")){//正数负数运算
+    				resultNum =getNumberFromText()*(-1);
+    		}
+    		isOperateValidFlag(operateValidFlag);
+    		firstDigit = true;//复位
+    		if (operateValidFlag == false) processText.setText(null);
+    		operateValidFlag = true;
+    	}
+
+    	
+    	private void doOperator2(String key){//进行双目运算
+    		if (operator.equals("÷")){//除法运算//如果当前结果文本框中的值等于0
+    		 if (getNumberFromText()== 0.0){
+    		  operateValidFlag = false;//操作不合法
+    		  resultText.setFont(new Font("黑体", Font.BOLD, 40));
+    		  resultText.setText("除数不能为零");
+    		  //resultText.setFont(new Font("黑体", Font.BOLD, 55));
+    		} else {
+    		resultNum /= getNumberFromText();
+    		}
+    		} else if (operator.equals("+")){//加法运算
+    		resultNum += getNumberFromText();
+    		} else if (operator.equals("－")){//减法运算
+    		resultNum -= getNumberFromText();
+    		} else if (operator.equals("×")){//乘法运算
+    		resultNum *= getNumberFromText();
+    		} else if (operator.equals("=")){//赋值运算
+    			resultNum = getNumberFromText();
+    			processText.setText(null);
+    		} else if (operator.equals("aⁿ")){
+    			resultNum = Math.pow(resultNum, getNumberFromText());
+    		}	
+    		if (key.equals("+")|| key.equals("×")|| key.equals("÷")|| key.equals("=")){
+    			processText.setText(processText.getText()+ resultText.getText()+ key);
+    		} else if (key.equals("－")){
+    			 processText.setText(processText.getText()+ resultText.getText()+"-");
+    		} else if (key.equals("aⁿ")){
+    			   processText.setText(processText.getText()+ resultText.getText()+"^");
+    		}
+    		
+    		isOperateValidFlag(operateValidFlag);
+    		operator = key;//运算符为用户按的按钮
+    		firstDigit = true;
+    		if (operateValidFlag == false){
+    		processText.setText(null);
+    		}
+    		operateValidFlag = true;
+    	}
+   
+    		private void isOperateValidFlag(boolean operateValidFlag) {
+    		if(operateValidFlag){//操作合法的情况下，将小数点后的位数进行处理
+    		long t1 =(long) resultNum;
+    		double t2 = resultNum - t1;//得到小数部分
+    		BigDecimal bd = new BigDecimal(String.valueOf(resultNum));//得到小数位数
+    		if (t2 == 0){
+    		resultText.setText(String.valueOf(t1));//转化为字符串
+    		} else if (bd.scale()== 1){
+    		resultText.setText(String.valueOf(new DecimalFormat("0.0").format(resultNum)));
+    		} else if (bd.scale()== 2){
+    		resultText.setText(String.valueOf(new DecimalFormat("0.00").format(resultNum)));
+    		} else if (bd.scale()== 3){
+    		resultText.setText(String.valueOf(new DecimalFormat("0.000").format(resultNum)));
+    		} else if (bd.scale()== 4){
+    		resultText.setText(String.valueOf(new DecimalFormat("0.0000").format(resultNum)));
+    		} else if (bd.scale()== 5){
+    		resultText.setText(String.valueOf(new DecimalFormat("0,00000").format(resultNum)));
+    		} else if (bd.scale()== 6){
+    			resultText.setText(String.valueOf(new DecimalFormat("0.000000").format(resultNum)));
+    		} else if (bd.scale()== 7){
+    			resultText.setText(String.valueOf(new DecimalFormat("0.0000000").format(resultNum)));
+    		} else if (bd.scale()== 8){
+    			resultText.setText(String.valueOf(new DecimalFormat("0.00000000").format(resultNum)));
+    		} else {
+    			resultText.setText(String.valueOf(new DecimalFormat("0.000000000").format(resultNum)));
+    		}
+    	}
+    }
+    		private double getNumberFromText() {
+    			double result = 0;
+    			try {
+    				result = Double.valueOf(resultText.getText()).doubleValue();
+    			} catch (NumberFormatException e){
+    			}
+    			return result;
+    		}
+    		public static void main(String[] args){
+				new Calculator();
+		}
+  }
+
+
+    	
+    	
+    	
+    	
+    	
+    	
+    	
+    	
+    	
+    	
+    	
+    	

src/CalculatorGUI.java

@@ -2,78 +2,94 @@ import javax.swing.*;
 import java.awt.*;
 import java.awt.datatransfer.Clipboard;
 import java.awt.datatransfer.StringSelection;
-import java.awt.event.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.List;
 
-public class CalculatorGUI extends JFrame {
-
-    private List<String> history;
-    private JTextField displayField;
+public class CalculatorGUI extends JFrame implements ActionListener {
+    private JTextArea displayArea;
+    private JTextField inputField;
+    private ArrayList<String> history;
     private JTextArea historyArea;
 
     public CalculatorGUI() {
         history = new ArrayList<>();
 
+        // Set up the frame
         setTitle("Calculator");
+        setSize(400, 500);
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
-        setResizable(true);
         setLayout(new BorderLayout());
 
-        JPanel buttonPanel = new JPanel(new GridLayout(5, 4));
-        String[] buttonLabels = {
-                "7", "8", "9", "/",
+        // Display area
+        JPanel displayPanel = new JPanel(new GridLayout(1, 2));
+        inputField = new JTextField();
+        inputField.setEditable(false);
+        displayPanel.add(inputField);
+        historyArea = new JTextArea();
+        JScrollPane scrollPane = new JScrollPane(historyArea);
+        displayPanel.add(scrollPane);
+        add(displayPanel, BorderLayout.NORTH);
+
+        // Buttons
+        JPanel buttonPanel = new JPanel(new GridLayout(4, 4));
+        String[] buttonLabels = {"7", "8", "9", "/",
                 "4", "5", "6", "*",
                 "1", "2", "3", "-",
-                "C", "0", "=", "+",
-                "x²", "x³", "√x", "x⁴"
-        };
+                "C", "0", "=", "+"};
         for (String label : buttonLabels) {
             JButton button = new JButton(label);
-            button.addActionListener(new ButtonListener());
+            button.addActionListener(this);
             buttonPanel.add(button);
         }
+        add(buttonPanel, BorderLayout.CENTER);
 
-        displayField = new JTextField(20);
-        displayField.setEditable(false);
-        displayField.setHorizontalAlignment(SwingConstants.RIGHT);
-
-        historyArea = new JTextArea(10, 20);
-        historyArea.setEditable(false);
-        JScrollPane scrollPane = new JScrollPane(historyArea);
-
+        // Save, Copy, Clear buttons
         JPanel controlPanel = new JPanel(new FlowLayout());
-        JButton saveButton = new JButton("Save History");
+        JButton saveButton = new JButton("Save");
         saveButton.addActionListener(new SaveListener());
-        JButton copyButton = new JButton("Copy Selection");
+        JButton copyButton = new JButton("Copy");
         copyButton.addActionListener(new CopyListener());
-        JButton clearButton = new JButton("Clear History");
+        JButton clearButton = new JButton("Clear");
         clearButton.addActionListener(new ClearListener());
         controlPanel.add(saveButton);
         controlPanel.add(copyButton);
         controlPanel.add(clearButton);
-
-        add(displayField, BorderLayout.NORTH);
-        add(buttonPanel, BorderLayout.CENTER);
-        add(scrollPane, BorderLayout.EAST);
         add(controlPanel, BorderLayout.SOUTH);
 
-        pack();
         setVisible(true);
     }
 
-    //将给定的条目加入到历史记录中
-    private void appendToHistory(String entry) {
-        history.add(entry);
-        displayHistory();
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        String command = e.getActionCommand();
+        switch (command) {
+            case "C":
+                inputField.setText("");
+                break;
+            case "=":
+                calculate();
+                break;
+            default:
+                inputField.setText(inputField.getText() + command);
+        }
+    }
+
+    private void calculate() {
+        String expression = inputField.getText();
+        try {
+            String result = String.valueOf(eval(expression));
+            history.add(expression + " = " + result);
+            displayHistory();
+            inputField.setText(result);
+        } catch (NumberFormatException | ArithmeticException e) {
+            inputField.setText("Error");
+        }
     }
 
-    // 递归下降解析的方法
-    // 从表达式的最底层开始，逐步向上解析表达式的不同部分
-    // 直到整个表达式都被解析完，计算，最终得到表达式的结果。
     private double eval(String expression) {
         return new Object() {
             int pos = -1, ch;
@@ -137,7 +153,6 @@ public class CalculatorGUI extends JFrame {
         }.parse();
     }
 
-    //将每个条目以换行符分隔的形式显示在界面上的一个历史记录·文本区域中。
     private void displayHistory() {
         StringBuilder sb = new StringBuilder();
         for (String entry : history) {
@@ -146,117 +161,44 @@ public class CalculatorGUI extends JFrame {
         historyArea.setText(sb.toString());
     }
 
-    //特殊符号检测
-    private class ButtonListener implements ActionListener {
-        @Override
-        public void actionPerformed(ActionEvent e) {
-            String command = e.getActionCommand();
-            if (!command.equals("=")) {
-                if (command.equals("x²") || command.equals("x³") || command.equals("√x") || command.equals("x⁴")) {
-                    // 获取表达式和操作符
-                    String expression = displayField.getText();
-                    String operator = "";
-                    switch (command) {
-                        case "x²":
-                            operator = "²";
-                            break;
-                        case "x³":
-                            operator = "³";
-                            break;
-                        case "√x":
-                            operator = "√";
-                            break;
-                        case "x⁴":
-                            operator = "⁴";
-                            break;
-                    }
-                    // 计算函数值
-                    double result = calculateFunction(expression, command);
-                    // 构建历史记录字符串并添加到历史记录区
-                    String historyEntry = expression + operator + " = " + result;
-                    appendToHistory(historyEntry);
-                    // 显示结果在实时显示区
-                    displayField.setText(Double.toString(result));
-                } else if (command.equals("C")) {
-                    // 清除实时显示区域的算术式
-                    displayField.setText("");
-                } else {
-                    displayField.setText(displayField.getText() + command);
-                }
-            } else {
-                // Evaluate expression
-                String expression = displayField.getText();
-                try {
-                    double result = eval(expression);
-                    appendToHistory(expression + " = " + result);
-                    displayField.setText(Double.toString(result));
-                } catch (Exception ex) {
-                    appendToHistory("Error: " + ex.getMessage());
-                }
-            }
-        }
-    }
-
-    //特殊符号计算
-    private double calculateFunction(String expression, String function) {
-        // 根据不同的函数类型计算结果
-        double value = Double.parseDouble(expression);
-        switch (function) {
-            case "x²":
-                return value * value;
-            case "x³":
-                return value * value * value;
-            case "√x":
-                return Math.sqrt(value);
-            case "x⁴":
-                return value * value * value * value;
-            default:
-                return 0;
-        }
-    }
-
-    //历史记录保存
     private class SaveListener implements ActionListener {
         @Override
         public void actionPerformed(ActionEvent e) {
-            JFileChooser fileChooser = new JFileChooser();
-            int result = fileChooser.showSaveDialog(null);
-            if (result == JFileChooser.APPROVE_OPTION) {
-                File file = fileChooser.getSelectedFile();
-                try (FileWriter writer = new FileWriter(file)) {
-                    for (String entry : history) {
-                        writer.write(entry + "\n");
-                    }
-                    writer.flush();
-                    JOptionPane.showMessageDialog(null, "History saved successfully!");
-                } catch (IOException ex) {
-                    JOptionPane.showMessageDialog(null, "Error saving history: " + ex.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
+            try {
+                File file = new File("calculator_history.txt");
+                FileWriter writer = new FileWriter(file);
+                for (String entry : history) {
+                    writer.write(entry + "\n");
                 }
+                writer.close();
+                JOptionPane.showMessageDialog(CalculatorGUI.this, "History saved successfully");
+            } catch (IOException ex) {
+                ex.printStackTrace();
+                JOptionPane.showMessageDialog(CalculatorGUI.this, "Error saving history");
             }
         }
     }
 
-    //复制
     private class CopyListener implements ActionListener {
         @Override
         public void actionPerformed(ActionEvent e) {
-            StringSelection selection = new StringSelection(historyArea.getSelectedText());
-            Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
-            clipboard.setContents(selection, null);
-            JOptionPane.showMessageDialog(null, "Selection copied to clipboard!");
+            String selectedText = historyArea.getSelectedText();
+            if (selectedText != null) {
+                StringSelection selection = new StringSelection(selectedText);
+                Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
+                clipboard.setContents(selection, null);
+            }
         }
     }
 
-    //清除
     private class ClearListener implements ActionListener {
         @Override
         public void actionPerformed(ActionEvent e) {
             history.clear();
-            displayHistory();
+            historyArea.setText("");
         }
     }
 
-
     public static void main(String[] args) {
         new CalculatorGUI();
     }