java - JTextField 卡在 ActionListener 的特定文本上

Question

我有一个程序，其中应该选择 JMenuButtonItem，并且 ActionListener 使用所选内容更新 JTextField。但是，它仅显示在 buildPhonePackageMenu() 中预先选择为 true 的内容。如果参数中没有 true，则不会将单选按钮识别为已选择。buildPhoneModelMenu() 似乎工作正常。

谁能帮我弄清楚为什么一个菜单有效而另一个菜单无效？我花了 6 个小时试图弄清楚。谢谢!

    import javax.swing.*;

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

public class CellPhoneCalculator extends JFrame{

    private JMenuBar menuBar; //Menu bar to hold drop down menus.
    private JMenu fileMenu; //file menu
    private JMenu phonePackage; //menu containing phone packages and options
    private JMenu phoneModels; //menu containing cell phone models.
    private JMenuItem exit;//Exit button
    private JRadioButtonMenuItem package300; //300 minute cell phone package
    private JRadioButtonMenuItem package800; //800 minute cell phone package
    private JRadioButtonMenuItem package1500; //1500 minute cell phone package.
    private JRadioButtonMenuItem phone100;  //phone model 100
    private JRadioButtonMenuItem phone110; //phone model 110
    private JRadioButtonMenuItem phone200; //phone model 200
    private JCheckBoxMenuItem vmail; //voicemail option
    private JCheckBoxMenuItem text; //text messaging option

    private JLabel packageSelected;//Displays the text "Cell Phone Package:"
    private JLabel modelSelected; //Displays the text "Cell Phone Model:"
    private JLabel optionsSelected; //Displays the text "Options Selected:"
    private JLabel subtotal; //Displays the text "Subtotal."
    private JLabel tax; //Displays the text "Sales Tax (6%) :"
    private JLabel total; //Displays the text "Total:"
    private JTextField pSelected; //displays the selected cell phone package.
    private JTextField mSelected; //displays the selected cell phone model.
    private JTextField oSelectedV; //Displays the Voice Mail option selected.
    private JTextField oSelectedT; //Displays the Text option selected.
    private JTextField dspSub; //displays the subtotal
    private JTextField dspTax; //displays the sales tax amount on subtotal
    private JTextField dspTotal; //displays the total after tax.

    public CellPhoneCalculator()
    {
        //call the superclass constructor to instantiate a JFrame
        //with a String argument to be title.
        super("Cell Phone Package Pricing Calculator");

        //Exit on window close
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        buildPricePane();//builds the price panel to go into content pane
        buildMenuBar();//Builds the menu bar.
        buildPhonePackageMenu();//Builds phone package menu
        buildFileMenu();//Builds the File Menu


        //pack method to resize JFrame.
        pack();
        //Set visibility of panel.
        setVisible(true);
    }

    private void buildMenuBar()
    {
        menuBar = new JMenuBar();//Create the menu bar

        buildFileMenu(); //build the file menu
        buildPhonePackageMenu();//build the phone package menu
        buildPhoneModelMenu();//build the phone model menu
        //Add the menus to the menuBar.
        menuBar.add(fileMenu);
        menuBar.add(phonePackage);
        menuBar.add(phoneModels);

        setJMenuBar(menuBar);//sets the menu bar for the window.
    }

    private void buildPhonePackageMenu()
    {
        phonePackage = new JMenu("Cell Phone Packages");//Drop down containing phone plan
                                                    //packages and options.

        //Make the radio buttons for cell phone packages.
        package300 = new JRadioButtonMenuItem("300 minute package", true);
        package800 = new JRadioButtonMenuItem("800 minute package");
        package1500 = new JRadioButtonMenuItem("1500 minute package");

        //Register the action listener PackageListener with the radio buttons.
        package300.addActionListener(new PackageListener());
        package800.addActionListener(new PackageListener());
        package1500.addActionListener(new PackageListener());

        //Make new button group for packages so buttons are mutually exclusive.
        ButtonGroup packages = new ButtonGroup();

        //Add radio buttons to packages button group.
        packages.add(package300);
        packages.add(package800);
        packages.add(package1500);

        //Create phone option check boxes.
        vmail = new JCheckBoxMenuItem("Voice Mail");
        text = new JCheckBoxMenuItem("Text Mail");

        //Register Item Listener with check box options.
        vmail.addItemListener(new OptionsListener());
        text.addItemListener(new OptionsListener());

        //Add components to menu
        phonePackage.add(package300);
        phonePackage.add(package800);
        phonePackage.add(package1500);
        phonePackage.addSeparator();//Add a separator before phone options
        phonePackage.add(vmail);
        phonePackage.add(text);

    }

    private void buildFileMenu()
    {
        //Instantiate file drop down with text "File."
        fileMenu = new JMenu("File");
        //Create exit button
        exit = new JMenuItem("Exit");
        //register action listener
        exit.addActionListener(new ExitButtonListener());
        //add exit menu item to menu
        fileMenu.add(exit);

    }
    /*
     * Build the menu to select the phone models.
     */
    private void buildPhoneModelMenu()
    {
        //Create Menu drop down with text "Phone Models."
        phoneModels = new JMenu("Phone Models");
        //Create new radio buttons in menu, with model 100 preselected.
        phone100 = new JRadioButtonMenuItem("Phone Model 100", true);
        phone110 = new JRadioButtonMenuItem("Phone Model 110");
        phone200 = new JRadioButtonMenuItem("Phone Model 200");

        //Register the ActionListener modelListener with the buttons.
        phone100.addActionListener(new ModelListener());
        phone110.addActionListener(new ModelListener());
        phone200.addActionListener(new ModelListener());

        //Create new phone model button group.
        ButtonGroup phoneModel = new ButtonGroup();
        //Add phone model radio buttons to button group, so they're selection is mutually exclusive.
        phoneModel.add(phone100);
        phoneModel.add(phone110);
        phoneModel.add(phone200);

        //Add the buttons to the menu.
        phoneModels.add(phone100);
        phoneModels.add(phone110);
        phoneModels.add(phone200);

    }
        private DecimalFormat dollar = new DecimalFormat("###.##");
        /*
         * Construct the PricePane with all components.
         */
        public void buildPricePane()
        {
            //Create the JPanel object and assign to pricePanel.
            JPanel pricePanel = new JPanel();
            setLayout(new GridLayout(13,1));

            //Create the text labels for left hand column
            packageSelected = new JLabel("Cell Phone Package: ");
            modelSelected = new JLabel("Cell Phone Model: ");
            optionsSelected = new JLabel("Options Selected: ");
            subtotal = new JLabel("Subtotal: ");
            tax = new JLabel("Sales Tax (6%): ");
            total = new JLabel("Total: ");

            //Create the Un-Editable text fields to display selected radio button items
            pSelected = new JTextField("", 10);
            pSelected.setEditable(false);

            mSelected = new JTextField("", 10);
            mSelected.setEditable(false);

            //Create the Un-Editable text fields to display selected check box items.
            oSelectedV = new JTextField(10);
            oSelectedV.setEditable(false);
            oSelectedT = new JTextField(10);
            oSelectedT.setEditable(false);

            //Create the un-editable text fields to display subtotal, tax and total.
            dspSub = new JTextField("", 10);
            dspSub.setEditable(false);
            dspTax = new JTextField("", 10);
            dspTax.setEditable(false);
            dspTotal = new JTextField("", 10);
            dspTotal.setEditable(false);

            //Add the items and labels to JPanel.
            add(packageSelected);
            add(pSelected);
            add(modelSelected);
            add(mSelected);
            add(optionsSelected);
            add(oSelectedV);
            add(oSelectedT);
            add(subtotal);
            add(dspSub);
            add(tax);
            add(dspTax);
            add(total);
            add(dspTotal);

        }

    /*
     * ActionListener interface for the cell phone package radio buttons.
     * Sends text and prices to PricePane, to display and sum respectively.
     */
    private class PackageListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            if(package300.isSelected())
                pSelected.setText("300 minutes per month: $45.00 per month");//Sends display text
            if(package800.isSelected())
                pSelected.setText("800 minutes per month: $65.00 per month");
            if(package1500.isSelected())
                pSelected.setText("1500 minutes per month: $99.00 per month");

        }
    }
    /*
     * ItemListener interface for the cell phone options check boxes.
     */
    private class OptionsListener implements ItemListener
    {
        public void itemStateChanged(ItemEvent e)
        {
            if(vmail.isSelected())
                oSelectedV.setText("Voice mail: $5.00 per month");
            if(text.isSelected())
                oSelectedT.setText("Text messaging: $10.00");
        }
    }
    /*
     * ActionListener for the cell phone model radio buttons.
     */
    private class ModelListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            if(phone100.isSelected())
                mSelected.setText("Model 100: $29.95");
            if(phone110.isSelected())
                mSelected.setText("Model 110: $49.95");
            if(phone200.isSelected())
                mSelected.setText("Model 200: $99.95");

        }
    }


    /*
     * ActionListener interface for exit button to close application.
     */
    private class ExitButtonListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            System.exit(0);
        }
    }
    /*
     * Main function to launch GUI.
     */
    public static void main(String[] args)
    {
        new CellPhoneCalculator();
    }
}

Answer 1

    buildPhonePackageMenu();//Builds phone package menu

这行在 公共(public) CellPhoneCalculator()

需要删除。我搞砸了。无视。