JComboBox with Vector

[Guy Shahar]

I am trying to make a drop-down JComboBox with its options taken from a Vector. The problem is that when I add a new String to the Vector, the JComboBox becomes empty rather than displaying the updated options.

I had the same problem with a JList, but for this I was able to substitute a DefaultListModel for a Vector and it worked fine. Unfortunately, this option does not seem to be available for a JComboBox.

Can anybody help???

[Michael Dunn]

seems to work OK like this

    
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
class Testing extends JFrame
{
  Vector vec = new Vector(Arrays.asList(new String[]{"London","Madrid","New York","Rome","Sydney","Washington"}));
  JComboBox cbo = new JComboBox(vec);
  public Testing()
  {
    setLocation(400,300);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    JPanel jp = new JPanel();
    JButton btn = new JButton("Add");
    jp.add(cbo);
    jp.add(btn);
    getContentPane().add(jp);
    pack();
    btn.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent ae){
        String newCity = JOptionPane.showInputDialog(getContentPane(),"Add City:");
        vec.add(newCity);
        cbo.setModel(new DefaultComboBoxModel(vec));
        }});
  }
  public static void main(String args[]){new Testing().setVisible(true);}
}
 

[Guy Shahar]

Thanks Michael. I have messed around a bit and found a way to make it work (not sure how).