java gui 简易计算器

以下是一个Java Swing的GUI图形用户界面编程设计并编写的简易计算器程序，用户可以通过鼠标或键盘输入参加运算的数值和运算符，进行简单的四则运算：

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

public class Calculator extends JFrame implements ActionListener {
    private static final long serialVersionUID = 1L;
    private JTextField textField;
    private JButton[] buttons;
    private String[] buttonLabels = { "7", "8", "9", "/", "4", "5", "6", "*", "1", "2", "3", "-", "0", ".", "=", "+" };
    private double num1, num2, result;
    private String operator;

    public Calculator() {
        super("Calculator");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());
        textField = new JTextField();
        add(textField, BorderLayout.NORTH);
        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new GridLayout(4, 4));
        buttons = new JButton[buttonLabels.length];
        for (int i = 0; i < buttonLabels.length; i++) {
            buttons[i] = new JButton(buttonLabels[i]);
            buttons[i].addActionListener(this);
            buttonPanel.add(buttons[i]);
        }
        add(buttonPanel, BorderLayout.CENTER);
        pack();
        setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        String label = e.getActionCommand();
        if (label.equals("C")) {
            textField.setText("");
        } else if (label.equals("=")) {
            num2 = Double.parseDouble(textField.getText());
            if (operator.equals("+")) {
                result = num1 + num2;
            } else if (operator.equals("-")) {
                result = num1 - num2;
            } else if (operator.equals("*")) {
                result = num1 * num2;
            } else if (operator.equals("/")) {
                result = num1 / num2;
            }
            textField.setText(Double.toString(result));
        } else if (label.equals("+") || label.equals("-") || label.equals("*") || label.equals("/")) {
            num1 = Double.parseDouble(textField.getText());
            operator = label;
            textField.setText("");
        } else {
            textField.setText(textField.getText() + label);
        }
    }

    public static void main(String[] args) {
        new Calculator();
    }
}