我有一个数据库模式 = 它将作为 JTable 列显示在 JCombobox 中以选择名称。但我希望将 ID 字段插入(作为外键)到另一个表中。
通常,在下拉列表中选择一个项目,将所选项目带到组合框的显示区域。
我想要做的是,当在组合框中选择任何项目(字符串)时,其对应的整数键(可以保存在排序映射中)应该显示在组合框占位符区域中,以便在取值时JTable.getValueAt(row, column),我得到整数键,而不是字符串项值。 请帮助我,我该怎么做?
最佳答案
您应该在包含要显示的字符串值和键的整数值的 TableModel 中存储一个对象。然后你访问 table.getValueAt(...) 你可以访问包含这两条信息的对象。
这是一个独立组合框的示例:
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 );
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 );
}
}
关于java - JCombobox 字符串项(可见)和整数键(固有),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4822928/