Java：Swing JComboBox，是否可以为列表中的每个项目隐藏数据？

Java: Swing JComboBox, is it possible to have hidden data for each item in the list?

提问by evilReiko

JComponents can obtain hidden data using setName()and getName(), right? What about JComboBox items? (I'm referring to the itemsin the JComboBox, NOT the JComboBox itself)

JComponents 可以使用setName()and获取隐藏数据getName()，对吗？JComboBox 项目呢？（我指的是 JComboBox 中的项目，而不是 JComboBox 本身）

What if I have a JComboBox, and inside it I have a list of usernames (for example), now I want to have something like 'id' for each username in the list according to how they are ordered, what's the best way to do this?

如果我有一个 JComboBox，并且在其中我有一个用户名列表（例如），现在我想根据它们的排序方式为列表中的每个用户名设置类似“id”的东西，最好的方法是什么这？

回答by camickr

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.plaf.basic.*;

public class ComboBoxItem extends JFrame implements ActionListener
{
    public ComboBoxItem()
    {
        Vector model = new Vector();
        model.addElement( new Item(1, "car" ) );
        model.addElement( new Item(2, "plane" ) );
        model.addElement( new Item(3, "train" ) );
        model.addElement( new Item(4, "boat" ) );
        model.addElement( new Item(5, "boat aadf asfsdf a asd asd" ) );

        JComboBox comboBox;

        //  Easiest approach is to just override toString() method
        //  of the Item class

        comboBox = new JComboBox( model );
        comboBox.addActionListener( this );
        comboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
        getContentPane().add(comboBox, BorderLayout.NORTH );

        //  Most flexible approach is to create a custom render
        //  to diplay the Item data

        comboBox = new JComboBox( model );
        comboBox.setRenderer( new ItemRenderer() );
        comboBox.addActionListener( this );
        getContentPane().add(comboBox, BorderLayout.SOUTH );
    }

    public void actionPerformed(ActionEvent e)
    {
        JComboBox comboBox = (JComboBox)e.getSource();
        Item item = (Item)comboBox.getSelectedItem();
        System.out.println( item.getId() + " : " + item.getDescription() );
    }

    class ItemRenderer extends BasicComboBoxRenderer
    {
        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;
        }
    }

    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;
        }

        public String toString()
        {
            return description;
        }
    }

    public static void main(String[] args)
    {
        JFrame frame = new ComboBoxItem();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setVisible( true );
     }

}

回答by Akna

Your object :

你的对象：

public class Item {

    private int id;
    private String name;

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

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String toString(){
        return this.name;
    }
}

Add items to your JComboBox :

将项目添加到您的 JComboBox ：

JComboBox combo;

combo.addItem(new Item(1, "Test"));
combo.addItem(new Item(15,"Test 2"));

And get Item :

并获得项目：

Item selected_item = (Item) combo.getSelectedItem();

System.out.println(selected_item.getId());
System.out.println(selected_item.getName());

回答by atamanroman

Create a Userclass which has the attributes usernameand id; return only usernamein .toString().

创建一个User具有属性username和的类id；仅username在.toString().