Combo Boxes-JComboBox

JComboBox

JComboBox is the combination of a text field and a drop down. The user can select a value from the drop-down list, which appears on the list. The combo box contains an editable field.

Declaration of JComboBox Class

public class JComboBox<E>
      extends JComponent
           implements ItemSelectable, ActionListner Accessible

where,
E: the type of element of this combo box

JComboBox Class Constructors

ConstructorDescription
JComboBox()Creates the JComboBox with default data model.
JComboBox(ComboBoxModel<E>  model)Creates a JComboBox that takes its items from an existing ComboBoxModel.
JComboBox(E[ ]  items)Creates a JComboBox that contains the elements in the specified array.
JComboBox(Vector<E> items)Creates a JComboBox that contains the elements in the specified Vector.

Example of using JComboBox, JTextField and JButton

// JComboDemo.java

import java.awt.Color;
import java.awt.event.*;
import javax.swing.*;
public class JComboDemo
{
     public static void main(String args[])
     {
          final JComboBox combo;
          final JTextField txt;
          JButton b1 = new JButton("Show");
          String sports[] = {"Cricket", "Football", "Tennis", "Badminton", "Hockey", "Wrestling"};
          JFrame frame = new JFrame("JComboBoxDemo");
          JPanel panel = new JPanel();
          combo = new JComboBox(sports);
          combo.setForeground(Color.pink);
          txt = new JTextField(20);
          panel.add(combo);
          panel.add(txt);
          panel.add(b1);
          frame.add(panel);
          combo.addItemListener(new ItemListener()
          {
               @Override
               public void itemStateChanged(ItemEvent ie)
               {
                    String str = (String)combo.getSelectedItem();
                    txt.setText(str);
               }
          });
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          frame.setSize(430, 200);
          frame.setVisible(true);
     }
}


Output:

jcombo box
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