package xzk;

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 num1Field, num2Field, resultField;
    private JComboBox<String> operatorBox;

    public Calculator() {

        super("简单计算器");


        setLayout(new BorderLayout());

        // 创建面板
        JPanel inputPanel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(5, 5, 5, 5); // 设置组件之间的间距

        // 创建输入字段和标签
        gbc.gridx = 0;
        gbc.gridy = 0;
        inputPanel.add(new JLabel("第一个数字:"), gbc);
        gbc.gridx = 1;
        num1Field = new JTextField(10);
        inputPanel.add(num1Field, gbc);

        gbc.gridy = 1;
        gbc.gridx = 0;
        inputPanel.add(new JLabel("第二个数字:"), gbc);
        gbc.gridx = 1;
        num2Field = new JTextField(10);
        inputPanel.add(num2Field, gbc);

        gbc.gridy = 2;
        gbc.gridx = 0;
        inputPanel.add(new JLabel("操作符:"), gbc);
        gbc.gridx = 1;
        operatorBox = new JComboBox<>(new String[]{"+", "-", "*", "/", "%"});
        inputPanel.add(operatorBox, gbc);

        gbc.gridy = 3;
        gbc.gridx = 0;
        inputPanel.add(new JLabel("结果:"), gbc);
        gbc.gridx = 1;
        resultField = new JTextField(10);
        resultField.setEditable(false);
        inputPanel.add(resultField, gbc);

        // 创建计算按钮
        JButton calculateButton = new JButton("计算");
        gbc.gridy = 4;
        gbc.gridx = 0;
        gbc.gridwidth = 2;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        inputPanel.add(calculateButton, gbc);

        // 添加事件监听器
        calculateButton.addActionListener(this);

        // 设置面板背景色
        inputPanel.setBackground(Color.LIGHT_GRAY);

        // 将面板添加到窗口
        add(inputPanel, BorderLayout.CENTER);

        // 设置窗口属性
        setSize(400, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null); // 窗口居中显示
        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        try {
            double num1 = Double.parseDouble(num1Field.getText());
            double num2 = Double.parseDouble(num2Field.getText());
            String operator = (String) operatorBox.getSelectedItem();
            double result;

            switch (operator) {
                case "+":
                    result = num1 + num2;
                    break;
                case "-":
                    result = num1 - num2;
                    break;
                case "*":
                    result = num1 * num2;
                    break;
                case "/":
                    if (num2 != 0) {
                        result = num1 / num2;
                    } else {
                        JOptionPane.showMessageDialog(this, "错误：除数不能为零");
                        return;
                    }
                    break;
                case "%":
                    if (num2 != 0) {
                        result = num1 % num2;
                    } else {
                        JOptionPane.showMessageDialog(this, "错误：除数不能为零");
                        return;
                    }
                    break;
                default:
                    JOptionPane.showMessageDialog(this, "无效的操作符!");
                    return;
            }

            resultField.setText(String.format("%.2f", result));
        } catch (NumberFormatException ex) {
            JOptionPane.showMessageDialog(this, "请输入有效的数字");
        }
    }

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