开发者

Removing an item from the JList using ListModel as model type

I have the JList which is using ListModel and not the DefaultListModel. I don't want to change the type now because I am using this in many places. I want to remove a selected item from the same list. How do i do this? I am using the following code but its not working for me.

made_list.removeSelectionInterval(
    made_list.getSelectedIndex(), made_list.getSelectedIndex());

--EDIT--

I am using the following code when I create my list:

made_list = new javax.swing.JList();   
made_list.setModel(new DefaultListModel());

And then in the JButton mouseclick event, I am using the following code to remove the selected item from the list when the button is pressed

private void removeActionPerformed(java.awt.event.ActionEvent evt) {                                       
    //made_list.removeSelectionInterval(made_list.getSelectedIndex(), 
    //made_list.getSelectedIndex());  
    System.out.println(made_list.getModel());  
    DefaultListModel model = (DefaultListModel)made_list开发者_如何学Go.getModel();  
    model.remove(1);  
}


removeSelectionInterval removes nothing from the model or the list except the selection interval. The list items remain unscathed. I'm afraid that you're either going to have to extend your ListModel and give it a removeItem(...) method as well as listeners and the ability to fire notifiers, etc... a la AbstractListModel -- quite a lot of work! If it were my money, though, I'd go the easy route and simply use a DefaultListModel for my model as it is a lot safer to do it this way, a lot easier, and will take a lot less time. I know you state that you don't want to use these, but I think you'll find it a lot easier than your potential alternatives.

An example of an SSCCE is something like this:

import java.awt.event.*;
import javax.swing.*;

public class Foo1 {
   private String[] elements = {"Monday", "Tueday", "Wednesday"};
   private javax.swing.JList made_list = new javax.swing.JList();

   public Foo1() {
      made_list.setModel(new DefaultListModel());
      for (String element : elements) {
         ((DefaultListModel) made_list.getModel()).addElement(element);
      }

      JButton removeItemBtn = new JButton("Remove Item");
      removeItemBtn.addActionListener(new ActionListener() {
         @Override
         public void actionPerformed(ActionEvent e) {
            removeActionPerformed(e);
         }
      });

      JPanel panel = new JPanel();
      panel.add(new JScrollPane(made_list));
      panel.add(removeItemBtn);

      JOptionPane.showMessageDialog(null, panel);
   }

   private void removeActionPerformed(ActionEvent e) {
      System.out.println("made_list's model: " + made_list.getModel());
      System.out.println("Model from a fresh JList: " + new JList().getModel());
      DefaultListModel model = (DefaultListModel) made_list.getModel();
      if (model.size() > 0) {
         model.remove(0);
      }
   }

   public static void main(String[] args) {
      new Foo1();
   }

}


You've been given a link to different sections of the Swing tutorial in the past to help solve problems. This was done for a reason. It helps solve your current problem. It gives you a reference for future problems.

All you need to do is look at the Table of Contents for the Swing tutorial and you will find a section on "How to Use Lists" which has a working example that adds/removes items from a list. Please read the tutorial first.

Or if you can't remember how to find the Swing tutorial then read the JList API where you will find a link to the same tutorial.


//First added  item into the list
DefaultListModel dlm1=new DefaultListModel();

listLeft.setModel(dlm1);

dlm1.addElement("A");
dlm1.addElement("B");
dlm1.addElement("C");

// Removeing element from list
Object[] temp=listRight.getSelectedValues();
if(temp.length>0)
{
for(int i=0;i<temp.length;i++)
{

  dlm1.removeElement(temp[i]);

}
}                   
0

上一篇:

下一篇:

精彩评论

暂无评论...
验证码 换一张
取 消

最新问答

问答排行榜