在Java中的不同面板之间切换以创建GUI界面

Question

我正在尝试编写一个程序，根据用户选择（使用AWT和Swing的所有GUI）将Celsius转换为Fahrenheit或Fahrenheit Celsius。

如何允许一种方法更改其他方法的可见性，以便更改程序的哪些部分可见？

以下是我的代码，因为我的确切问题很难解释：

package javapp1;

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

/**
 *
 * @author logan
 */
public class FahrenheitToCelsius extends JFrame
{
    private JPanel startPanel;
    private JPanel fahrenheitToCelsiusPanel;
    private JPanel celsiusToFahrenheitPanel;
    private JLabel decideLabel;
    private JLabel FahrenheitToCelsiusLabel;
    private JLabel CelsiusToFahrenheitLabel;
    private JTextField FahrenheitToCelsiusText;
    private JTextField CelsiusToFahrenheitText;
    private JButton fahrenheitButton;
    private JButton celsiusButton;
    private JButton calcButton;
    private JButton exitButton;
    private JButton backButton;
    private final int WINDOW_WIDTH = 400;
    private final int WINDOW_HEIGHT = 100;

    public FahrenheitToCelsius()
    {
        setTitle("Fahrenheit/Celsius Conversion");
        setSize(WINDOW_WIDTH,WINDOW_HEIGHT);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        buildStartPanel();
        add(startPanel);
    }

    private void buildStartPanel()
    {
        decideLabel = new JLabel("Would you like to convert from Celsius or Fahrenheit?");

        fahrenheitButton = new JButton("Fahrenheit");

        fahrenheitButton.addActionListener(new FahrenheitToCelsiusListener());

        celsiusButton = new JButton("Celsius");

        celsiusButton.addActionListener(new CelsiusToFahrenheitListener());

        exitButton = new JButton("Exit");

        exitButton.addActionListener(new ExitButtonListener());

        startPanel = new JPanel();

        startPanel.add(decideLabel);
        startPanel.add(fahrenheitButton);
        startPanel.add(celsiusButton);

        setVisible(true);
    }

    private void buildFahrenheitToCelsiusPanel()
    {   
        FahrenheitToCelsiusLabel = new JLabel("Enter the degrees Fahrenheit");

        FahrenheitToCelsiusText = new JTextField(10);

        calcButton = new JButton("Calculate");
        calcButton.addActionListener(new CalculateFtoC());

        exitButton = new JButton("Exit");
        exitButton.addActionListener(new ExitButtonListener());

        backButton = new JButton("Back");
        backButton.addActionListener(new BackButtonListener());

        fahrenheitToCelsiusPanel = new JPanel();

        fahrenheitToCelsiusPanel.add(FahrenheitToCelsiusLabel);
        fahrenheitToCelsiusPanel.add(FahrenheitToCelsiusText);
        fahrenheitToCelsiusPanel.add(calcButton);
        fahrenheitToCelsiusPanel.add(exitButton);
    }

    private void buildCelsiusToFahrenheitPanel()
    {
        CelsiusToFahrenheitLabel = new JLabel("Enter the degree Celsius");

        CelsiusToFahrenheitText = new JTextField(10);

        calcButton = new JButton("Calculate");
        calcButton.addActionListener(new CalculateCtoF());

        exitButton = new JButton("Exit");
        exitButton.addActionListener(new ExitButtonListener());

        backButton = new JButton("Back");
        backButton.addActionListener(new BackButtonListener());

        celsiusToFahrenheitPanel = new JPanel();

        celsiusToFahrenheitPanel.add(CelsiusToFahrenheitLabel);
        celsiusToFahrenheitPanel.add(CelsiusToFahrenheitText);
        celsiusToFahrenheitPanel.add(calcButton);
        celsiusToFahrenheitPanel.add(exitButton);

    }

    private class FahrenheitToCelsiusListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            startPanel.setVisible(false);
            celsiusToFahrenheitPanel.setVisible(false);
            buildFahrenheitToCelsiusPanel();

        }
    }

    private class CelsiusToFahrenheitListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            startPanel.setVisible(false);
            fahrenheitToCelsiusPanel.setVisible(false);
            buildCelsiusToFahrenheitPanel();
        }
    }

    private class ExitButtonListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            System.exit(0);
        }
    }

    private class BackButtonListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            fahrenheitToCelsiusPanel.setVisible(false);
            celsiusToFahrenheitPanel.setVisible(false);
            buildStartPanel();
        }
    }

    private class CalculateFtoC implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            String input;
            int celsius;
            int fahrenheit;

            input = FahrenheitToCelsiusText.getText();

            fahrenheit = Integer.parseInt(input);

            celsius = ((fahrenheit-32)*(5/9));

            JOptionPane.showMessageDialog(null, fahrenheit+" degrees fahrenheit is "+celsius+" degrees celsius.");
        }
    }

    private class CalculateCtoF implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            String input;
            int celsius;
            int fahrenheit;

            input = CelsiusToFahrenheitText.getText();

            celsius = Integer.parseInt(input);

            fahrenheit = ((celsius*(9/32))+32);

            JOptionPane.showMessageDialog(null, celsius+" degrees celsius is "+fahrenheit+" degrees fahrenheit.");
        }
    }

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