JavaJComboBox。setModel在操作期间保留选择

Question

我将有一些行为，我希望与其他一些jcombox耦合，因此我使用setModel()将数组作为值填充。在执行此操作并运行gui时，我注意到在选择了与第一个不同的元素后，组合框中没有显示其他元素。例如

正如您所看到的，它没有说charTwo，尽管这是我选择的。这是代码

注意：第101行是setModel()发生的地方

import org.apache.commons.lang3.ArrayUtils;

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

import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.border.TitledBorder;

public class TestGui extends JFrame {
    private final String[] guiCharSelDefault = {"---  Select Character ---"};
    private final String[] characters = {"charOne", "charTwo", "charThree", "charFour"};
    private final String[] GuiCharSel = (String[]) ArrayUtils.addAll(guiCharSelDefault, characters);
    private JComboBox charCombo = createStandardCombo(GuiCharSel);
    private BackgroundPanel backgroundFrame = createBackgroundFrame("../images/Background.png");
    private JPanel topFrame = createTopFrame();
    private JScrollPane topFrameScroll = createTopScrollPane();
    private JPanel centerFrame = createCenterFrame();

    //**************************************************************************************
    // Constructor

    TestGui(){
        setContentPane(backgroundFrame);
        add(topFrameScroll, BorderLayout.NORTH);
        add(centerFrame, BorderLayout.CENTER);

        setSize(800,600);
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    //**************************************************************************************
    // Support Methods
    private static GridBagConstraints setGbc(int gridx, int gridy, int gridWidth, int gridHeight, int ipadx, int ipady, String anchorLocation, double weightx, double weighty, Insets insets){
        GridBagConstraints gbc = new GridBagConstraints();

        if (anchorLocation.toUpperCase().equals("NORTHWEST")){
            gbc.anchor = GridBagConstraints.NORTHWEST;
        } else if (anchorLocation.toUpperCase().equals("NORTH")){
            gbc.anchor = GridBagConstraints.NORTH;
        } else if (anchorLocation.toUpperCase().equals("NORTHEAST")){
            gbc.anchor = GridBagConstraints.NORTHEAST;
        } else if (anchorLocation.toUpperCase().equals("WEST")){
            gbc.anchor = GridBagConstraints.WEST;
        } else if (anchorLocation.toUpperCase().equals("EAST")){
            gbc.anchor = GridBagConstraints.EAST;
        } else if (anchorLocation.toUpperCase().equals("SOUTHWEST")){
            gbc.anchor = GridBagConstraints.SOUTHWEST;
        } else if (anchorLocation.toUpperCase().equals("SOUTH")){
            gbc.anchor = GridBagConstraints.SOUTH;
        } else if (anchorLocation.toUpperCase().equals("SOUTHEAST")){
            gbc.anchor = GridBagConstraints.SOUTHEAST;
        } else {
            gbc.anchor = GridBagConstraints.CENTER;
        }

        gbc.gridx = gridx; // column
        gbc.gridy = gridy; // row
        gbc.gridwidth = gridWidth; // number of columns
        gbc.gridheight = gridHeight; // number of rows
        gbc.ipadx = ipadx; // width of object
        gbc.ipady = ipady; // height of object
        gbc.weightx = weightx; // shifts rows to side of set anchor
        gbc.weighty = weighty; // shifts columns to side of set anchor
        gbc.insets = insets; // placement inside cell
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.fill = GridBagConstraints.VERTICAL;

        return gbc;
    }

    private Insets setInsets(int top, int left, int bottom, int right){
        Insets insets = new Insets(top,left,bottom,right);
        return insets;
    }

    //**************************************************************************************
    // Interactive Object Methods

    private JComboBox createStandardCombo(String[] defaultValues){
        JComboBox comboBox = new JComboBox(defaultValues);
        DefaultListCellRenderer dlcr = new DefaultListCellRenderer();
        dlcr.setHorizontalAlignment(DefaultListCellRenderer.CENTER);
        comboBox.setRenderer(dlcr);
        comboBox.setPrototypeDisplayValue("X" + guiCharSelDefault + "X");
        return comboBox;
    }

    //**************************************************************************************
    // Object Action Methods

    private void setCharComboAction(){
        charCombo.addActionListener(
                new ActionListener() {
                    public void actionPerformed(ActionEvent e) {
                        String charName = ((JComboBox)(e.getSource())).getSelectedItem().toString();
                        if (!(charName.equals(guiCharSelDefault[0]))){
                            charCombo.setModel(new DefaultComboBoxModel(characters));
                        }
                    }
                }
        );
    }

    //**************************************************************************************
    // Panel Methods

    private BackgroundPanel createBackgroundFrame(String imgLocName){
        Image backgroundImg = null;
        try {
            backgroundImg = ImageIO.read(getClass().getResource(imgLocName));
            System.out.println("File: " + imgLocName.toString());
        } catch (Exception e) {
            System.out.println("Cannot read file: " + e);
        }
        BackgroundPanel bgPanel = new BackgroundPanel(backgroundImg, BackgroundPanel.SCALED, 0.0f, 0.0f);
        return bgPanel;
    }

    private JPanel createTopFrame(){
        JPanel pnl = new JPanel();

        pnl.setLayout(new GridBagLayout());

        setCharComboAction();
        pnl.add(charCombo, setGbc(0,0, 1,1, 0,0, "WEST", 0, 0, setInsets(0, 10, 0, 0)));

        pnl.setOpaque(false);
        return pnl;
    }

    private JScrollPane createTopScrollPane(){
        JScrollPane scrollPane = new JScrollPane(backgroundFrame);
        Border raisedBevel = BorderFactory.createRaisedBevelBorder();
        Border lineBorder = BorderFactory.createMatteBorder(2, 2, 2, 2, new Color(224,224,224));
        Border loweredBevel = BorderFactory.createLoweredBevelBorder();
        Border compoundSetup = BorderFactory.createCompoundBorder(raisedBevel, lineBorder);
        Border compoundFinal = BorderFactory.createCompoundBorder(compoundSetup, loweredBevel);

        scrollPane.setBorder(compoundFinal);
        scrollPane.setOpaque(false);
        scrollPane.getViewport().setOpaque(false);
        scrollPane.getViewport().setView(topFrame);
        return scrollPane;
    }

    private JPanel createCenterFrame() {
        JPanel pnl = new JPanel();
        Border raisedBevel = BorderFactory.createRaisedBevelBorder();
        Color lineColor = new Color(224, 224, 224);
        Border lineBorder = BorderFactory.createMatteBorder(5, 5, 5, 5, lineColor);
        Border loweredBevel = BorderFactory.createLoweredBevelBorder();
        Border compoundSetup = BorderFactory.createCompoundBorder(raisedBevel, lineBorder);
        Border compoundFinal = BorderFactory.createCompoundBorder(compoundSetup, loweredBevel);
        TitledBorder topFrameTitle = BorderFactory.createTitledBorder(compoundFinal, "Stuff");
        topFrameTitle.setTitleJustification(TitledBorder.CENTER);

        pnl.setBorder(topFrameTitle);
        pnl.setLayout(new GridBagLayout());

        pnl.setOpaque(false);
        return pnl;
    }

    //**************************************************************************************

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

有没有办法让它在选择后保留所选项目

Answer 1

为什么不恢复选择

private void setCharComboAction(){
    charCombo.addActionListener(
            new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    String charName = ((JComboBox)(e.getSource())).getSelectedItem().toString();
                    if (!(charName.equals(guiCharSelDefault[0]))){
                        DefaultComboBoxModel model = new DefaultComboBoxModel(characters);
                        model.setSelectedItem(charName);
                        charCombo.setModel(model);
                    }
                }
            }
    );
}