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

public class Calculator extends JFrame implements ActionListener {
    private JTextField textField;
    private double num1, num2, result;
    private String operator;

    public Calculator() {
        // 设置窗口基本属性
        setTitle("计算器");
        setSize(400, 600);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());

        // 创建文本框
        textField = new JTextField();
        textField.setFont(new Font("Arial", Font.PLAIN, 24));
        add(textField, BorderLayout.NORTH);

        // 创建按钮面板
        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(5, 4, 10, 10));
        String[] buttonLabels = {
                "7", "8", "9", "/",
                "4", "5", "6", "*",
                "1", "2", "3", "-",
                "0", "C", "=", "+",
                "%", "(", ")", ""
        };

        for (String label : buttonLabels) {
            JButton button = new JButton(label);
            button.setFont(new Font("Arial", Font.PLAIN, 24));
            button.addActionListener(this);
            panel.add(button);
        }

        add(panel, BorderLayout.CENTER);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();

        switch (command) {
            case "C":
                textField.setText("");
                break;
            case "=":
                num2 = Double.parseDouble(textField.getText());
                switch (operator) {
                    case "+":
                        result = num1 + num2;
                        break;
                    case "-":
                        result = num1 - num2;
                        break;
                    case "*":
                        result = num1 * num2;
                        break;
                    case "/":
                        if (num2 == 0) {
                            textField.setText("错误: 除以零");
                            return;
                        }
                        result = num1 / num2;
                        break;
                    case "%":
                        result = num1 % num2;
                        break;
                }
                textField.setText(String.valueOf(result));
                break;
            case "+":
            case "-":
            case "*":
            case "/":
            case "%":
                num1 = Double.parseDouble(textField.getText());
                operator = command;
                textField.setText("");
                break;
            default:
                textField.setText(textField.getText() + command);
                break;
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            Calculator calculator = new Calculator();
            calculator.setVisible(true);
        });
    }
}