無法在 case switch 語句中更改 if 語句

Question

我試圖從 switch 語句中的 if 語句內部更改 if 語句中使用的 int 的值，但是我無法弄清楚如何在不創建變量的新實例的情況下更改該值。

問題所在的類在主類中，代碼需要其余的類，但它們並不相關。 然而，當用戶在 gui 命令框中輸入一個數字時，FramePanel 類會初始化 decisionChooser 方法。

下面是我的完整代碼。 在主類下，您可以找到相關的 if 和 switch 語句：

主要類：

public class Main
{
    public static void main(String[] args)
    {
        FramePanel.runLater();
        StoryArray.main();
    }

    public int a1;
    public int a2;
    public int a3;
    public int a4;
    public int a5;
    public int textNumber;
    public String chosenText;


    public void decisionChooser()
    {
        String inputText = FramePanel.commandsField.getText();
        FramePanel.commandsField.setText(null);
        try
        {
            textNumber = Integer.parseInt(inputText);
            textNumber = textNumber - 1;

            if (textNumber == a1 || textNumber == a2 || textNumber == a3 || textNumber == a4 || textNumber == a5)
            {
                System.out.println(textNumber + " in If");

                System.out.println("Entering switch");
                switch (textNumber)
                {
                    case 0:
                        a1 = 70; // this will change a1 for in the if statement
                        chosenText = StoryArray.storyLine[textNumber];
                        FramePanel.currentTextArea.append(chosenText + "\n");
                        break;

                    case 70:
                        a1 = 281;
                        chosenText = StoryArray.storyLine[textNumber];
                        FramePanel.currentTextArea.append(chosenText + "\n");
                        break;

                    default:
                        break;
                }
            }
            else
            {
                FramePanel.currentTextArea.append("\nPlease choose a valid page number!\n");
            }
            System.out.println("Out of If statement");
        }
        catch (NumberFormatException NFE)
        {
            FramePanel.currentTextArea.append("Please Enter the Page number" + "\n");
        }
        System.out.println("looped");
    }
}

FramePanel 類：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.util.Random;
import javax.swing.*;

@SuppressWarnings("serial")
public class FramePanel extends JPanel
{
    /////Setting Positioning/////

    // rows and cols for jtextarea
    private static final int CURRENT_AREA_ROWS = 20;
    private static final int CURRENT_AREA_COLS = 40;

    // columns for command jtextfied
    private static final int COMMANDS_FIELD_COLS = 50;

    // size of GUI component gaps
    private static final int EB_GAP = 1;

    private String inventoryString()
    {
        return ("Inventory:" +
                "\n- " +
                "\n- " +
                "\n- " +
                "\n- " +
                "\n- " +
                "\n- " +
                "\n- " +
                "\n- " +
                "\n- " +
                "\n- ");
    }

    private String startString()
    {
        return ("Welcome to Warlock of Firetop Mountain! This game was coded by Thomas Thorburn and the story line was written by Ian Livingstone and Steve Jackson. To get started, click 'New Game' or load a save. If you get stuck click the 'Help' button or read the 'Help and Information' document.\n\nLet the Adventure Begin!");
    }
    private EnterAction enterAction = new EnterAction("Enter");

    public static JTextArea currentTextArea = new JTextArea(CURRENT_AREA_ROWS, CURRENT_AREA_COLS);
    public static JTextField commandsField = new JTextField(COMMANDS_FIELD_COLS);
    public static JTextArea inventoryTextArea = new JTextArea(CURRENT_AREA_ROWS, CURRENT_AREA_COLS);



    public FramePanel()
    {

        JPanel topBtnPanel = new JPanel(new GridLayout(1, 0));
        {
            topBtnPanel.add(new JButton(new HelpAction("Help", KeyEvent.VK_X)));
            topBtnPanel.add(new JButton(new RollAction("Roll Dice", KeyEvent.VK_X)));
            topBtnPanel.add(new JButton(new NewGameAction("New Game", KeyEvent.VK_X)));
            topBtnPanel.add(new JButton(new SaveAction("Save", KeyEvent.VK_X)));
            topBtnPanel.add(new JButton(new LoadAction("Load", KeyEvent.VK_X)));
        }

        JPanel characteristicsPanel = new JPanel(new GridBagLayout());
        {
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.anchor = GridBagConstraints.WEST;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.gridx = 1;
            gbc.gridy = 0;
            characteristicsPanel.add(new JTextField("20"), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JTextField("20"), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JTextField("20"), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JTextField("20"), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JTextField("20"), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JTextField("20"), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JTextField("20"), gbc);
            gbc.gridy ++;

            gbc.anchor = GridBagConstraints.EAST;
            gbc.gridx = 0;
            gbc.gridy = 0;
            characteristicsPanel.add(new JLabel("SKILL:  "), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JLabel("STAMINA:  "), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JLabel("LUCK:  "), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JLabel("GOLD:  "), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JLabel("JEWELS:  "), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JLabel("POTIONS:  "), gbc);
            gbc.gridy ++;
            characteristicsPanel.add(new JLabel("PREVISIONS:  "), gbc);
            gbc.gridy ++;
        }

        inventoryTextArea.setWrapStyleWord(true);
        inventoryTextArea.setLineWrap(true);
        inventoryTextArea.setEditable(true);
        inventoryTextArea.append(inventoryString());
        JScrollPane imgListPane = new JScrollPane(inventoryTextArea);
        imgListPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

        JPanel rightPanel = new JPanel(new BorderLayout(EB_GAP, EB_GAP));
        rightPanel.add(topBtnPanel, BorderLayout.PAGE_START);
        rightPanel.add(imgListPane, BorderLayout.CENTER);
        rightPanel.add(characteristicsPanel, BorderLayout.LINE_END);

        currentTextArea.setWrapStyleWord(true);
        currentTextArea.setLineWrap(true);
        currentTextArea.setFocusable(false);
        currentTextArea.append(startString());
        JScrollPane taScrollPane = new JScrollPane(currentTextArea);
        taScrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

        JPanel centerPanel = new JPanel(new BorderLayout());
        centerPanel.add(taScrollPane, BorderLayout.CENTER);
        centerPanel.add(rightPanel, BorderLayout.LINE_END);

        JPanel commandsPanel = new JPanel();
        commandsPanel.setLayout(new BoxLayout(commandsPanel, BoxLayout.LINE_AXIS));
        commandsPanel.add(commandsField);
        commandsPanel.add(Box.createHorizontalStrut(EB_GAP));
        commandsPanel.add(new JButton(enterAction));
        commandsPanel.add(Box.createHorizontalStrut(EB_GAP));
        commandsField.setAction(enterAction); // use same action for button and


        setBorder(BorderFactory.createEmptyBorder(EB_GAP, EB_GAP, EB_GAP, EB_GAP));
        setLayout(new BorderLayout(EB_GAP, EB_GAP));
        add(centerPanel, BorderLayout.CENTER);
        add(commandsPanel, BorderLayout.PAGE_END);
    }


    /////////Buttons/////////
    //Enter Button Action
    private class EnterAction extends AbstractAction
    {
        public EnterAction(String name)
        {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            Main mainChoices = new Main();//Allowing me to call Main
            mainChoices.decisionChooser();//Calling up decisionChooser method
        }
    }

    //Help Action
    private class HelpAction extends AbstractAction
    {
        public HelpAction (String name, int mnemonic)
        {
            super(name);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            currentTextArea.append("\n\n" + "Welcome to Warlock of Firetop Mountain! To navigate the story line just enter the relevant page number in the text box below, To make this game as authentic as possiable to the original game, all combat stats and inventory are controlled by the user. \n\nTo Save, Load or start a New Game, use the corresponding buttons in the top right of the window. To roll the dice you also click the 'Roll Dice' button. This will print the two dice rolls in your storyline box. For more information, please refer to the help and information guide provided with this program." + "\n \n");
        }
    }

    //New Game Button and Action
    private class NewGameAction extends AbstractAction
    {
        public NewGameAction (String name, int mnemonic)
        {
            super(name);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            currentTextArea.setText(startString());
        }
    }

    //Load Button and Action
    private class LoadAction extends AbstractAction
    {
        public LoadAction (String name, int mnemonic)
        {
            super(name);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            OpenFile of = new OpenFile();

            try
            {
                of.PickMe();
            }
            catch (Exception e1)
            {
                e1.printStackTrace();
            }
            currentTextArea.setText(of.sb.toString());
        }
    }

    //Save Button and Action
    private class SaveAction extends AbstractAction
    {
        public SaveAction (String name, int mnemonic)
        {
            super(name);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            System.out.print("yo3");
        }
    }

    //Exit Button and Action
    private class ExitAction extends AbstractAction
    {
        public ExitAction(String name, int mnemonic)
        {
            super(name);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            Component source = (Component) e.getSource();
            Window win = SwingUtilities.getWindowAncestor(source);
            win.dispose();
        }
    }

    //Roll Button Action
    private class RollAction extends AbstractAction
    {
        public RollAction(String name, int mnemonic)
        {
            super(name);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            Random r = new Random();

            int diceRoll1=r.nextInt(6); //Generates random number
            int diceRoll2=r.nextInt(6);


            diceRoll1 = diceRoll1 + 1; //Changes range from 0-5 to 1-6
            diceRoll2 = diceRoll2 + 1;

            currentTextArea.append("You have rolled a " + diceRoll1 + " and a " + diceRoll2 + "!" + "\n");
        }
    }


    /////////GUI Setup/////////
    //Making and choosing settings for frame.
    private static void createAndShowGUI()
    {
        FramePanel mainPanel = new FramePanel();

        JFrame frame = new JFrame("Warlock of Firetop Mountain");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(true);
        frame.setLocationRelativeTo(null);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }


    /////////Getters and Setters/////////
    //Getter for currentTextArea
    public static JTextArea getTextArea()
    {
        return currentTextArea;
    }


    /////////Run Later/////////
    public static void runLater()
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowGUI();
            }
        });
    }
}

打開文件類：

import javax.swing.*;
import java.util.Scanner;

public class OpenFile
{
    JFileChooser loadFile = new JFileChooser();
    StringBuilder sb = new StringBuilder();

    public void PickMe() throws Exception
    {
        if(loadFile.showOpenDialog(null) == JFileChooser.APPROVE_OPTION)
        {
            java.io.File file = loadFile.getSelectedFile();


            Scanner input = new Scanner(file);

            while (input.hasNext())
            {
                sb.append(input.nextLine());
                sb.append("\n\n");
            }
            input.close();

        }
        else
        {
            sb.append("\n\n" + "No File Selected! \n\n");

        }
    }
}

StoryArray 類（由於字符串數量而縮短）：

public class StoryArray
{
    public static String storyLine[] = null ;
    public static String[] getStoryLine()
    {
        return storyLine;
    }
    public static void main()
    {
        //String[] storyLine;
        storyLine = new String[399];
        storyLine[0] = ("test1");
        storyLine[1] = ("test2");
        storyLine[2] = ("test 3");
        storyLine[18] = ("test4");

        storyLine[69] = ("Test5");
        storyLine[70] = ("Test6");
        storyLine[71] = ("Test7");
        storyLine[73] = ("Test8");
    }
}

Answer 1

我意識到將變量設為公開並不會使其成為類變量。 這意味着每次我運行循環時，它都會創建一個新的變量實例。 為了改變這一點並使它成為一個類變量，我必須將它聲明為靜態的，這意味着只能有一個實例，所以每次我運行循環並更改 switch 語句中的值時，它會更改外部的值循環也是如此。

這是我必須聲明的方式：

public static int textNumber;