Java中规模软件开发实训——简单计算器制作

import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
public class Calculator extends JFrame implements ActionListener {
private JTextField displayField;
private double num1, num2;
private char operator;
private List<String> history;

public Calculator() {
    setTitle("计算器");
    setSize(320, 420);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new BorderLayout());
    setResizable(false);

    // 设置天空蓝色背景
    Color skyBlue = new Color(135, 206, 250);
    getContentPane().setBackground(skyBlue);

    // 创建菜单栏
    JMenuBar menuBar = new JMenuBar();
    setJMenuBar(menuBar);

    // 创建"查看历史记录"菜单
    JMenu historyMenu = new JMenu("历史记录");
    menuBar.add(historyMenu);

    // 创建历史记录菜单项
    JMenuItem viewHistoryMenuItem = new JMenuItem("查看历史记录");
    viewHistoryMenuItem.addActionListener(e -> {
        String message = "";
        for (String entry : history) {
            message += entry + "\n";
        }
        JOptionPane.showMessageDialog(this, message, "历史记录", JOptionPane.INFORMATION_MESSAGE);
    });
    historyMenu.add(viewHistoryMenuItem);

    JPanel contentPane = new JPanel();
    contentPane.setBorder(new EmptyBorder(10, 10, 10, 10));
    contentPane.setLayout(new BorderLayout());
    contentPane.setBackground(skyBlue);
    add(contentPane, BorderLayout.CENTER);

    displayField = new JTextField();
    displayField.setEditable(false);
    displayField.setHorizontalAlignment(JTextField.RIGHT);
    displayField.setPreferredSize(new Dimension(280, 50));
    displayField.setFont(new Font("黑体", Font.PLAIN, 20));
    contentPane.add(displayField, BorderLayout.NORTH);

    JPanel buttonPanel = new JPanel();
    buttonPanel.setLayout(new GridLayout(6, 4, 5, 5));
    buttonPanel.setBackground(skyBlue);

    String[] buttons = {
            "%", "CE", "C", "删除",
            "1/x", "平方", "√", "/",
            "7", "8", "9", "*",
            "4", "5", "6", "-",
            "1", "2", "3", "+",
            "±", "0", ".", "="
    };

    for (String button : buttons) {
        JButton btn = new JButton(button);
        btn.addActionListener(this);
        btn.setBackground(Color.WHITE);
        btn.setFont(new Font("黑体", Font.PLAIN, 18));
        buttonPanel.add(btn);
    }

    contentPane.add(buttonPanel, BorderLayout.CENTER);

    history = new ArrayList<>();
}

@Override
public void actionPerformed(ActionEvent e) {
    String command = e.getActionCommand();
    switch (command) {
        case "C":
            displayField.setText("");
            break;
        case "CE":
            displayField.setText("");
            num1 = 0;
            num2 = 0;
            operator = '\u0000';
            break;
        case "删除":
            String text = displayField.getText();
            if (!text.isEmpty()) {
                displayField.setText(text.substring(0, text.length() - 1));
            }
            break;
        case "+":
        case "-":
        case "*":
        case "/":
            num1 = Double.parseDouble(displayField.getText());
            operator = command.charAt(0);
            displayField.setText("");
            break;
        case "=":
            num2 = Double.parseDouble(displayField.getText());
            double result = calculate(num1, num2, operator);
            displayField.setText(Double.toString(result));
            history.add(num1 + " " + operator + " " + num2 + " = " + result);
            break;
        case "±":
            double value = Double.parseDouble(displayField.getText());
            value = -value;
            displayField.setText(Double.toString(value));
            break;
        case "1/x":
            double reciprocal = 1 / Double.parseDouble(displayField.getText());
            displayField.setText(Double.toString(reciprocal));
            break;
        case "平方":
            double square = Math.pow(Double.parseDouble(displayField.getText()), 2);
            displayField.setText(Double.toString(square));
            break;
        case "√":
            double squareRoot = Math.sqrt(Double.parseDouble(displayField.getText()));
            displayField.setText(Double.toString(squareRoot));
            break;
        default:
            displayField.setText(displayField.getText() + command);
    }
}

private double calculate(double num1, double num2, char operator) {
    double result = 0;
    switch (operator) {
        case '+':
            result = num1 + num2;
            break;
        case '-':
            result = num1 - num2;
            break;
        case '*':
            result = num1 * num2;
            break;
        case '/':
            result = num1 / num2;
            break;

    }
    return result;
}

public static void main(String[] args) {
    try {
        // 设置Look and Feel为系统默认
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    } catch (Exception e) {
        e.printStackTrace();
    }

    SwingUtilities.invokeLater(() -> {
        Calculator calculator = new Calculator();
        calculator.setVisible(true);
    });
}

}