用公制方程计算BMI，如何在Java中用图形用户界面实现英制测量换算

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

public class BMICalculator extends JFrame {
    private JTextField weightField;
    private JTextField heightField;
    private JLabel resultLabel;

    public BMICalculator() {
        setTitle("BMI Calculator");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(300, 200);
        setLocationRelativeTo(null);

        // 创建界面组件
        JLabel weightLabel = new JLabel("Weight (lbs):");
        weightField = new JTextField(10);
        JLabel heightLabel = new JLabel("Height (inches):");
        heightField = new JTextField(10);
        JButton calculateButton = new JButton("Calculate");
        resultLabel = new JLabel();

        // 设置布局
        setLayout(new FlowLayout());

        // 添加组件到窗口
        add(weightLabel);
        add(weightField);
        add(heightLabel);
        add(heightField);
        add(calculateButton);
        add(resultLabel);

        // 添加按钮点击事件监听器
        calculateButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                calculateBMI();
            }
        });
    }

    private void calculateBMI() {
        try {
            double weight = Double.parseDouble(weightField.getText());
            double height = Double.parseDouble(heightField.getText());

            // 英制转换为公制
            weight = weight * 0.45359237; // 磅转千克
            height = height * 0.0254; // 英寸转米

            // 计算BMI
            double bmi = weight / (height * height);

            // 显示结果
            resultLabel.setText("BMI: " + bmi);
        } catch (NumberFormatException ex) {
            resultLabel.setText("Invalid input");
        }
    }

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