Java Swing 计算器模拟程序 - 实现加减乘除运算

以下是一个使用 Java Swing 实现的简单计算器模拟程序，它可以进行整数的加、减、乘、除四则运算：

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Calculator {
    private JFrame frame;
    private JTextField num1Field;
    private JTextField num2Field;
    private JTextField resultField;

    public Calculator() {
        frame = new JFrame('Calculator');
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 200);
        frame.setLayout(new GridLayout(4, 2));

        JLabel num1Label = new JLabel('Number 1:');
        num1Field = new JTextField();
        JLabel num2Label = new JLabel('Number 2:');
        num2Field = new JTextField();
        JLabel resultLabel = new JLabel('Result:');
        resultField = new JTextField();
        resultField.setEditable(false);

        JButton addButton = new JButton('+');
        addButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int num1 = Integer.parseInt(num1Field.getText());
                int num2 = Integer.parseInt(num2Field.getText());
                int result = num1 + num2;
                resultField.setText(String.valueOf(result));
            }
        });

        JButton subtractButton = new JButton('-');
        subtractButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int num1 = Integer.parseInt(num1Field.getText());
                int num2 = Integer.parseInt(num2Field.getText());
                int result = num1 - num2;
                resultField.setText(String.valueOf(result));
            }
        });

        JButton multiplyButton = new JButton('*');
        multiplyButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int num1 = Integer.parseInt(num1Field.getText());
                int num2 = Integer.parseInt(num2Field.getText());
                int result = num1 * num2;
                resultField.setText(String.valueOf(result));
            }
        });

        JButton divideButton = new JButton('/');
        divideButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int num1 = Integer.parseInt(num1Field.getText());
                int num2 = Integer.parseInt(num2Field.getText());
                if (num2 == 0) {
                    resultField.setText('Error: Cannot divide by zero');
                } else {
                    int result = num1 / num2;
                    resultField.setText(String.valueOf(result));
                }
            }
        });

        frame.add(num1Label);
        frame.add(num1Field);
        frame.add(num2Label);
        frame.add(num2Field);
        frame.add(resultLabel);
        frame.add(resultField);
        frame.add(addButton);
        frame.add(subtractButton);
        frame.add(multiplyButton);
        frame.add(divideButton);

        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new Calculator();
            }
        });
    }
}

该程序使用了 Java 的 Swing 库来创建 GUI 界面。它包含一个 JFrame 窗口，其中包含两个文本框（用于输入两个整数），一个文本框（用于显示结果）和四个按钮（加、减、乘、除）。

每个按钮都添加了一个 ActionListener，当按钮被点击时，对应的操作会被执行。例如，点击 '+' 按钮会将两个输入的整数相加，并将结果显示在结果文本框中。

注意：在除法运算中，程序会检查除数是否为零，如果是，则显示错误消息。