Solved

How to use JComboBox

Posted on 2004-09-17
14
1,153 Views
Last Modified: 2008-03-10
I use a JComboBox in my program. What I want is: After I typed some text and pressed RETURN, the typed text will add to item.

I use the ActionListener (Is this a correct listener?), then I do follows:

...
jComboBox.addActionListener(new java.awt.event.ActionListener() {
  public void actionPerformed(java.awt.event.ActionEvent e) {    
    jComboBox.addItem(???);
...
}
What should it be for the ???


0
Comment
Question by:chenwei
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 7
  • 2
  • 2
14 Comments
 
LVL 37

Expert Comment

by:zzynx
ID: 12083001
jComboBox.addItem(yourTextField.getText());
0
 
LVL 37

Expert Comment

by:zzynx
ID: 12083009
>> After I typed some text and pressed RETURN
Oh, do you mean you type the text in the editable combo box?
0
 
LVL 37

Accepted Solution

by:
zzynx earned 20 total points
ID: 12083231
>> Oh, do you mean you type the text in the editable combo box?
So, you want to "remember" the manually entered items in the combo box for future use?

That is:

jComboBox.addActionListener(new java.awt.event.ActionListener() {

  public void actionPerformed(java.awt.event.ActionEvent e) {    
        if (!evt.getActionCommand().equals("comboBoxEdited")) return;
        jComboBox.addItem( jComboBox.getSelectedItem());      
  }

}
0
Get 15 Days FREE Full-Featured Trial

Benefit from a mission critical IT monitoring with Monitis Premium or get it FREE for your entry level monitoring needs.
-Over 200,000 users
-More than 300,000 websites monitored
-Used in 197 countries
-Recommended by 98% of users

 

Author Comment

by:chenwei
ID: 12083428
What's "comboBoxEdited"? The text I typed? How can the program know what text I will type?
0
 
LVL 37

Expert Comment

by:zzynx
ID: 12083468
>> What's "comboBoxEdited"? The text I typed?
Not at all.

actionPerformed() is triggered twice when pressing Enter:
once with actionCommand == "comboBoxChanged"
once with actionCommand == "comboBoxEdited"

To avoid the same item added twice you need that if statement.

Just try it.
0
 

Author Comment

by:chenwei
ID: 12083683
Thanks. But I solve my problem myself. I do folows:

...
public void actionPerformed(java.awt.event.ActionEvent e) {
 jComboBoxCommand.addItem(jComboBoxCommand.getSelectedItem());
...
...
0
 
LVL 37

Expert Comment

by:zzynx
ID: 12083739
You asked
>> What should it be for the ???
I answered. You use it now.
0
 
LVL 37

Expert Comment

by:zzynx
ID: 12084011
So, kindly accept my comment
0
 
LVL 3

Expert Comment

by:nesnemis
ID: 12090679
First, add an actionlistener to the textfield that you want to input your text

Then in actionPerformed add:
   combo.addItem(text.getText());

To make it easier to input many values you can also add this code after additem:
   text.setText("");
0
 
LVL 3

Expert Comment

by:nesnemis
ID: 12090681
The whole program is:

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JComboBox;
import javax.swing.JDialog;
import javax.swing.JPanel;
import javax.swing.JTextField;

/**
 * @author Espen
 */
public class ComboMaker extends JDialog implements ActionListener
{
      JTextField text;
      JComboBox combo;
      /**
       * Constructor for ComboMaker.
       */
      public ComboMaker()
      {
            super();
            
            JPanel panel = new JPanel();
            panel.setBackground(Color.BLUE);
            
            combo = new JComboBox();
            
            text = new JTextField(10);
            text.addActionListener(this);
            
            panel.add(text);
            panel.add(combo);
            
            getContentPane().add(panel);
            
            setSize(200, 200);
      }
      public void actionPerformed(ActionEvent ae)
      {
            if(ae.getSource() == text)
            {
                  combo.addItem(text.getText());
                  text.setText("");
            }
      }
}
0
 
LVL 37

Expert Comment

by:zzynx
ID: 12284395
The author says he solved his problem, but the code he gave is just a copy of my comment,
so I think my comment deserves to be accepted.
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction This article is the second of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers the basic installation and configuration of the test automation tools used by…
Java functions are among the best things for programmers to work with as Java sites can be very easy to read and prepare. Java especially simplifies many processes in the coding industry as it helps integrate many forms of technology and different d…
Viewers learn about the third conditional statement “else if” and use it in an example program. Then additional information about conditional statements is provided, covering the topic thoroughly. Viewers learn about the third conditional statement …
Viewers will learn about basic arrays, how to declare them, and how to use them. Introduction and definition: Declare an array and cover the syntax of declaring them: Initialize every index in the created array: Example/Features of a basic arr…

695 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question