java - 具有多个相同元素的 JComboBox 始终选择元素的第一个实例

Question

我有 6 个组合框，使用具有 6 个元素的相同 DefaultListModel。我使用 ActionListener，以便当其中一个组合框从另一个组合框选择的列表中选择一个元素时，它们会交换选择这些元素的人员。又名，组合框 1 选择了元素 1，选择了组合框 3 选择的元素 2，并且在监听器运行后，组合框 3 将选择元素 1。

ActionListener abilCBListener = new ActionListener(){
    @Override
    public void actionPerformed(ActionEvent evt){
        JComboBox cb = (JComboBox)evt.getSource();
        int ind = abilCBArray.indexOf(cb);
        int num = 15;
        int dup = 7;

        if(abilCBArray.size() == 6 && abilCBBoo == true){
            abilCBBoo = false;// prevents another combobox's listener from firing
            for(int i = 0; i < abilCBArray.size();i++){
                //System.out.println("i = " + i + " index = "+abilCBArray.get(i).getSelectedIndex());
                if(i != ind){
                    num -= abilCBArray.get(i).getSelectedIndex();
                    System.out.println("i = "+ i+" num = "+ num+ " Index = "+abilCBArray.get(i).getSelectedIndex() );
                    if(abilCBArray.get(i).getSelectedIndex() == cb.getSelectedIndex()){
                        dup = i;
                    } 
                }
            }
            if(num < abilCBArray.size() && dup != 7){
                abilCBArray.get(dup).setSelectedIndex(num);
            }
        }else{
            System.out.println("Tried to run abilCBArrayChange without full array");            
        }          
        abilCBBoo = true;
    }
};

问题是用户可以将一组随机数字放入 DefaultListModel 中，如果任何数字相同，组合框将选择该数字的第一个实例的索引，这会弄乱我的 ActionListener。我读到的所有内容似乎都表明您必须使列表中的每个项目都是唯一的才能解决组合框选择问题，并且我仍然无法使用 getSelectIndex() 因为如果我这样做，它仍然会返回第一个实例的数量。

Answer 1

@camickr

import java.awt.event.ActionEvent;
import javax.swing.*;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.util.Vector;

public class TestDuplicatesItems {

    private Vector<String> vec = new Vector<String>();
    private String[] degrees = {"AAS1", "AAS2", "AAS1", "AAS1"};
    private JComboBox combo = new JComboBox(vec);
    private JComboBox combo1 = new JComboBox(degrees);
    private JTextField txt = new JTextField(10);
    private JFrame frame = new JFrame("JComboBox with Duplicates Items");
    private JPanel panel = new JPanel();

    public TestDuplicatesItems() {
        vec.add("AAS1");
        vec.add("AAS1");
        vec.add("AAS1");
        vec.add("AAS1");
        //combo.setEditable(true);
        //combo.setBackground(Color.gray);
        //combo.setForeground(Color.red);        
        //combo.setEditable(true);
        //combo1.setBackground(Color.gray);
        //combo1.setForeground(Color.red);        
        txt.setText("1");
        combo.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println(combo.getSelectedIndex());
                System.out.println(combo.getSelectedItem().toString());
                txt.setText(String.valueOf(combo.getSelectedIndex()));
            }
        });
        combo1.addItemListener(new ItemListener() {

            @Override
            public void itemStateChanged(ItemEvent e) {
                if ((e.getStateChange() == ItemEvent.SELECTED)) {
                    System.out.println(combo1.getSelectedIndex());
                    System.out.println(combo1.getSelectedItem().toString());
                    txt.setText(String.valueOf(combo1.getSelectedIndex()));
                }
            }
        });
        panel.add(combo);
        panel.add(combo1);
        panel.add(txt);
        frame.add(panel);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                TestDuplicatesItems tdi = new TestDuplicatesItems();
            }
        });
    }
}

并且基于原始数组

import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.plaf.basic.BasicComboBoxRenderer;

public class SelectedComboBoxID {

    private JComboBox combo = new JComboBox();
    private JFrame frame = new JFrame("MyComboEg");
    private JTextField txt = new JTextField(10);
    private JPanel panel = new JPanel();

    public SelectedComboBoxID() {
        combo.addItem(new Item(1, "-"));
        combo.addItem(new Item(2, "Snowboarding"));
        combo.addItem(new Item(3, "Rowing"));
        combo.addItem(new Item(4, "Knitting"));
        combo.addItem(new Item(5, "Speed reading"));
        combo.addItem(new Item(6, "Pool"));
        combo.addItem(new Item(7, "None of the above"));
        //comboBox.setMaximumRowCount(3);
        combo.setPrototypeDisplayValue(" None of the above ");
        combo.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                JComboBox comboBox = (JComboBox) e.getSource();
                Item item = (Item) comboBox.getSelectedItem();
                System.out.println(item.getId() + " : " + item.getDescription());
                txt.setText(String.valueOf(combo.getSelectedIndex()));
            }
        });
        //comboBox.setRenderer(new ItemRenderer());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        panel.add(combo);
        panel.add(txt);
        frame.add(panel);
        frame.pack();
        //frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    private class ItemRenderer extends BasicComboBoxRenderer {

        private static final long serialVersionUID = 1L;

        @Override
        public Component getListCellRendererComponent(JList list, Object value,
                int index, boolean isSelected, boolean cellHasFocus) {
            super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
            if (value != null) {
                Item item = (Item) value;
                setText(item.getDescription().toUpperCase());
            }
            if (index == -1) {
                Item item = (Item) value;
                setText("" + item.getId());
            }
            return this;
        }
    }

    private class Item {

        private int id;
        private String description;

        public Item(int id, String description) {
            this.id = id;
            this.description = description;
        }

        public int getId() {
            return id;
        }

        public String getDescription() {
            return description;
        }

        @Override
        public String toString() {
            return description;
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                SelectedComboBoxID selectedComboBoxID = new SelectedComboBoxID();
            }
        });
    }
}