java - 如何对 JCheckBox 和 JTextField 使用单个 ActionListener

Question

我正在编写一个 eJuice 计算器。正如您将在下面看到的那样，它还远未完成。我的问题是:我有 4 个 JCheckBox 和 5 个可编辑的 JTextField；我可以使用一个 ActionListener 来让程序执行一些东西吗？或者我是否需要一个用于复选框的监听器和一个用于文本字段的监听器？

这是代码的草稿。

    package ejuicecalculatorv2;

    import java.awt.*;
    import java.awt.event.*;

    import javax.swing.*;

       public class EJuiceCalculatorV2 extends JFrame {
    //Form Controls
    private JCheckBox isPGbasedNic_CB       = new JCheckBox("PG Based NIC");
    private JCheckBox isPGbasedFlavor_CB    = new JCheckBox("PG Based Flavor");

    private JCheckBox isVGbasedNic_CB       = new JCheckBox("VG Based NIC");
    private JCheckBox isVGbasedFlavor_CB    = new JCheckBox("VG Based Flavor");

    private JTextField batchSize_TF         = new JTextField(5);
    private JLabel batchSize_LB             = new JLabel("Batch Size:");

    private JTextField baseNicStrength_TF   = new JTextField(5);
    private JLabel baseNicStrength_LB       = new JLabel("Base NIC Strength:");

    private JTextField targetNicStrength_TF = new JTextField(5);
    private JLabel targetNicStrength_LB     = new JLabel("Target NIC Strength:");

    private JTextField totalNic_TF          = new JTextField(5);
    private JLabel totalNic_LB              = new JLabel("Total NIC:");

    private JTextField flavorStrength_TF    = new JTextField(5);
    private JLabel flavorStrength_LB        = new JLabel("Flavoring Strength:");

    private JTextField totalFlavor_TF       = new JTextField(5);
    private JLabel totalFlavor_LB           = new JLabel("Total Flavoring:");

    private JTextField vgRatio_TF           = new JTextField(5);
    private JLabel vgRatio_LB               = new JLabel("VG Ratio:");

    private JTextField pgRatio_TF           = new JTextField(5);
    private JLabel pgRatio_LB               = new JLabel("PG Ratio:");

    private JTextField additionalVG_TF      = new JTextField(5);
    private JLabel additionalVG_LB          = new JLabel("Additional VG:");

    private JTextField additionalPG_TF      = new JTextField(5);
    private JLabel additionalPG_LB          = new JLabel("Additional PG:");

    private JTextField totalVG_TF           = new JTextField(5);
    private JLabel totalVG_LB               = new JLabel("Total VG:");

    private JTextField totalPG_TF           = new JTextField(5);
    private JLabel totalPG_LB               = new JLabel("Total PG:");

    private JTextField vgBasedIng_TF        = new JTextField(5);
    private JLabel vgBasedIng_LB            = new JLabel("Total VG Ingredients:");

    private JTextField pgBasedIng_TF        = new JTextField(5);
    private JLabel pgBasedIng_LB            = new JLabel("Total PG Ingredients:");


    //Variables
    private boolean _PGnicFlag;
    private boolean _VGnicFlag;

    private boolean _PGflavorFlag;
    private boolean _VGflavorFlag;

    private double baseNic;
    private double targetNic;
    private double totalNic;

    private double flavorStrength;
    private double totalFlavor;

    private double batchSize;

    private double totalPG;
    private double totalVG;

    private double additionalVG;
    private double additionalPG;

    private double pgBasedIng;
    private double vgBasedIng;

    private double pgRatio;
    private double vgRatio;


    public EJuiceCalculatorV2() {
        super("EJuice Calculator V2");
        setLayout(new FlowLayout());

        //Add CheckBoxes
        add(isPGbasedNic_CB);
        add(isPGbasedFlavor_CB);
        add(isVGbasedNic_CB);
        add(isVGbasedFlavor_CB);

        //Add TextFields and Labels
        add(batchSize_LB);
        add(batchSize_TF);

        add(vgRatio_LB);
        add(vgRatio_TF);

        add(pgRatio_LB);
        add(pgRatio_TF);

        add(baseNicStrength_LB);
        add(baseNicStrength_TF);

        add(targetNicStrength_LB);
        add(targetNicStrength_TF);

        add(flavorStrength_LB);
        add(flavorStrength_TF);

        //Add ActionListeners
        ActionListener actionListener = new ActionHandler();
        isPGbasedNic_CB.addActionListener(actionListener);
        isPGbasedFlavor_CB.addActionListener(actionListener);
        isVGbasedNic_CB.addActionListener(actionListener);
        isVGbasedFlavor_CB.addActionListener(actionListener);
        batchSize_TF.addActionListener(actionListener);
        vgRatio_TF.addActionListener(actionListener);
        pgRatio_TF.addActionListener(actionListener);
        baseNicStrength_TF.addActionListener(actionListener);
        targetNicStrength_TF.addActionListener(actionListener);
        flavorStrength_TF.addActionListener(actionListener);     


        pack();
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    class ActionHandler implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent event){

            //if event.getSource() == JCheckBox then execute the following code. 


            if(checkBox.isSelected()){
                if(checkBox == isPGbasedNic_CB){
                    _PGnicFlag = true;
                    _VGnicFlag = false;
                    checkBox = isVGbasedNic_CB;
                    checkBox.setSelected(false);                   
                }
                else if(checkBox == isVGbasedNic_CB){
                    _VGnicFlag = true;
                    _PGnicFlag = false;
                    checkBox = isPGbasedNic_CB;
                    checkBox.setSelected(false);
                }
                else if(checkBox == isVGbasedFlavor_CB){
                    _VGflavorFlag = true;
                    _PGflavorFlag = false;
                    checkBox = isPGbasedFlavor_CB;
                    checkBox.setSelected(false);
                }
                else if(checkBox == isPGbasedFlavor_CB){
                    _PGflavorFlag = true;
                    _VGflavorFlag = false;
                    checkBox = isVGbasedFlavor_CB;
                    checkBox.setSelected(false);
                }
            }
            else{
                if(checkBox == isPGbasedNic_CB){
                    _PGnicFlag = false;
                    _VGnicFlag = true;
                }
                else if(checkBox == isVGbasedNic_CB){
                    _VGnicFlag = false;
                    _PGnicFlag = true;
                }
                else if(checkBox == isVGbasedFlavor_CB){
                    _VGflavorFlag = false;
                    _PGflavorFlag = true;
                }
                else if(checkBox == isPGbasedFlavor_CB){
                    _PGflavorFlag = false;
                    _VGflavorFlag = true;
                }
            }
    }
}

public static void main(String[] args) {
        // TODO code application logic here
        SwingUtilities.invokeLater(new Runnable(){
            @Override
            public void run (){
                new EJuiceCalculatorV2().setVisible(true);
            }
        });
    }
}

Answer 1

My question is: I have 4 JCheckBoxes, and 5 editable JTextFields; can I use one ActionListener to do have the program execute stuff. Or do I need one listener for the CheckBoxes and one for the TextField?

您有一堆控制组件，但没有出现可以从 GUI 启动操作的组件。 JCheckBox 和 JTextField 等所有组件都是用来获取输入的，而您似乎缺少最后一个组件，例如 JButton。我会将此组件添加到您的 GUI 中，并且会向其中单独添加一个 ActionListener。然后，当按下时，它将检查复选框和文本组件的状态，然后根据它们的状态，为用户提供适当的响应。

还有一些(如果不是大多数或全部)JTextFields，我会更改为 JComboBoxes 或 JSpinners，以将用户可以输入的输入限制为允许的内容，因为您不希望用户输入"is" ”进入“批量大小”JTextField。

例如:

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import java.util.List;

import javax.swing.*;
import javax.swing.JSpinner.DefaultEditor;

@SuppressWarnings("serial")
public class JuiceTwo extends JPanel {
    private static final String[] FLAVORS = {"Flavor 1", "Flavor 2", "Flavor 3", "Flavor 4"};
    private static final Integer[] ALLOWABLE_BATCH_SIZES = {1, 2, 5, 10, 15, 20};
    private static final String[] ALLOWABLE_VG_RATIOS = {"1/4", "1/3", "1/2", "1/1", "2/1", "3/1", "4/1", "8/1", "16/1"};
    private List<JCheckBox> flavorBoxes = new ArrayList<>();
    private JComboBox<Integer> batchSizeCombo;
    private JSpinner vgRatioSpinner;

    public JuiceTwo() {

        // JPanel to hold the flavor JCheckBoxes
        JPanel flavorPanel = new JPanel(new GridLayout(0, 1)); // hold them in vertical grid
        flavorPanel.setBorder(BorderFactory.createTitledBorder("Flavors"));
        for (String flavor : FLAVORS) {
            JCheckBox flavorBox = new JCheckBox(flavor);
            flavorBox.setActionCommand(flavor);
            flavorPanel.add(flavorBox);
            flavorBoxes.add(flavorBox);
        }

        batchSizeCombo = new JComboBox<>(ALLOWABLE_BATCH_SIZES);

        SpinnerListModel vgRatioModel = new SpinnerListModel(ALLOWABLE_VG_RATIOS);
        vgRatioSpinner = new JSpinner(vgRatioModel);
        JComponent editor = vgRatioSpinner.getEditor();
        if (editor instanceof DefaultEditor) {
            ((DefaultEditor)editor).getTextField().setColumns(4);
        }


        JButton getSelectionButton = new JButton("Get Selection");
        getSelectionButton.setMnemonic(KeyEvent.VK_S);
        getSelectionButton.addActionListener(new SelectionActionListener());

        add(flavorPanel);
        add(Box.createHorizontalStrut(20));
        add(new JLabel("Batch Size:"));
        add(batchSizeCombo);
        add(Box.createHorizontalStrut(20));
        add(new JLabel("VG Ratio:"));
        add(vgRatioSpinner);
        add(Box.createHorizontalStrut(20));
        add(getSelectionButton);
    }

    private class SelectionActionListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            for (JCheckBox flavorBox : flavorBoxes) {
                System.out.printf("%s selected: %b%n", flavorBox.getActionCommand(), flavorBox.isSelected());
            }

            System.out.println("Batch Size: " + batchSizeCombo.getSelectedItem());            
            System.out.println("VG Ration:  " + vgRatioSpinner.getValue());

            System.out.println();
        }
    }

    private static void createAndShowGui() {
        JuiceTwo mainPanel = new JuiceTwo();

        JFrame frame = new JFrame("JuiceTwo");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }
}