如何在Java中控制多个JComboBoxes？

Question

I have trouble with setting up 12 comboboxes on a JDialog. The first 4 are the gender of 4 individuals. The second 4 are their personality types. The third 4 are their job titles.

How come when I change the 1st person's gender combobox, the 2nd, 3rd, 4th gender comboboxes are all being changed at the same time?

Why are they "linked" together? I already have separate ActionListeners for each?

The same thing with the personality comboboxes and the job comboboxes.

See attached pic.

What do I need to do to severe whatever linking them?

Also, Eclipse forces me to use "final" keyword on my customized JComboBoxMW.

Note that JComboBoxMW is nothing fancy. just extending the JComboBox class with better mouse wheel control.

See a portion of code below:

   public void setUpCrewGender() {

    List<String> genderList = new ArrayList<String>(2);
    genderList.add("M");
    genderList.add("F");
    genderComboBoxModel = new DefaultComboBoxModel<String>();
    Iterator<String> i = genderList.iterator();

    while (i.hasNext()) {
        String s = i.next();
        genderComboBoxModel.addElement(s);
    }



    final JComboBoxMW<String> g1 = new JComboBoxMW<String>(genderComboBoxModel);
    g1.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e1) {
            String s1 = (String) g1.getSelectedItem();
            g1.setSelectedItem(s1);
        }});  
    g1.setMaximumRowCount(2);
    listPane.add(g1);


    final JComboBoxMW<String> g2 = new JComboBoxMW<String>(genderComboBoxModel);
    g2.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e2) {
            String s2 = (String) g2.getSelectedItem();
            g2.setSelectedItem(s2);
        }});  
    g2.setMaximumRowCount(2);   
    listPane.add(g2);       

    final JComboBoxMW<String> g3 = new JComboBoxMW<String>(genderComboBoxModel);
    g3.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e3) {
            String s3 = (String) g3.getSelectedItem();
            g3.setSelectedItem(s3);
        }});  
    g3.setMaximumRowCount(2);
    listPane.add(g3);



    final JComboBoxMW<String> g4 = new JComboBoxMW<String>(genderComboBoxModel);
    g4.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e4) {
            String s4 = (String) g4.getSelectedItem();
            g4.setSelectedItem(s4);
        }});  
    g4.setMaximumRowCount(2);
    listPane.add(g4);

   }

Answer 1

All the JComboBoxes share the same model, ie, genderComboBoxModel , and thus will all the views will show the same model-state. Solution: give them unique models.

As an aside, consider using a JTable with JComboBox editors for your data entry.

Answer 2

You're using the same ComboBoxModel for each JComboBox , but the ComboBoxModel also manages the selected item, so when one combo box updates, all the other combo boxes are updated.

You need to create a separate/individual ComboBoxModel for each combo box which contains that data you want displayed instead