List Box : how to move multiple items in C# ?

[DjPal]

Hello,

I am trying to move multiple items from one list box to another, i have tried the following code, but the output so far just gives me "{collection}" in the other list box.

private void btnMoverr_Click(object sender, EventArgs e)
        {
 
            //lstBoxr.Items.Add(lstBoxl.SelectedItems);
            //lstBoxl.Items.Remove(lstBoxr.SelectedItems);
 
            while (lstBoxl.SelectedItems.Count > 0)
            {
 
                lstBoxr.Items.Add(lstBoxl.SelectedItems);
                lstBoxl.Items.Remove(lstBoxl.SelectedItems);
            }
 
 
            //lstBoxr.SelectedItems.Add(lstBoxl.SelectedItems);
            //lstBoxl.SelectedItems.Remove(lstBoxl.SelectedItems);
        }
 

i'm using C# in visual studio 2008, any ideas would be appreciated!

Thanks,
Pal

[Dheeraj Joshi]

You iterate through the collection of selected items and display one by one.... Basically you have the collection not individual items...

Regards
Dheeraj Joshi

[sanjib65]

Try the followng code, hopefully it will work. Actaually ListBox Control has an event called SelectedIndexChange(), to fire it I have used another Button but wrote nothing in its eventhandler because the Page_Load() method is !IsPostback. So when you select State in the first ListBox1, and click the Button, the second ListBox2 will take the value from the first one.

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
 
public partial class Default3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            ListBox1.Items.Add("anything");
            ListBox1.Items.Add("State");
            ListBox1.Items.Add("anything");
            ListBox1.Items.Add("anything");
        }
    }
    private void LoadListBox()
    {
        ListBox2.Items.Clear();
 
        ListBox2.Items.Add("West bengal");
        ListBox2.Items.Add("Assam");
        ListBox2.Items.Add("Maharashtra");
        ListBox2.Items.Add("Assam");
 
    }
    protected void ListBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (ListBox1.SelectedIndex == 1)
        {
            LoadListBox();
        }
    }
}
 

[Dheeraj Joshi]

Hey sanjib65,

You are not moving the items from one list box to other....

Selected index changed occurs when property of selected item changes. How you are relating this to the problem?

Regards
Dheeraj Joshi

[DjPal]

Thanks guys.. still havn't solved the issue yet but incase you think of anything more let me know! cheers.

[Dheeraj Joshi]

Basically you want to move items(Selected items of course) from one list box to other....? Am i right..?

Regards
Dheeraj Joshi

[DjPal]

Yes Dheeraj,
I have two list boxes, and i want to move multiple items (yes, selected) from one list box to another!

[sanjib65]

Sorry friends, probably I was in hurry and did not follow the problem. Actually what he wanted to do is clearing one ListBox and moving the Items from first to second. Have I understood it now properly? Please let me know so that I can have a try.

[tlhintoq]

There is a property of "SelectedIndexCollection". This will provide a list of numbers that are the indexes of the selected times of the ListBox. For example: if the first, third and tenth items were selected you would get indexes of 0,2,9

I suggest, copy the selected items to the second ListBox in one loop then remove the items *in reverse order* during a second loop.

The reason you remove in reverse order is because as soon you remove item 2, item 3 becomes 2, 4 becomes 3 and so on, invalidating the list. But if you take away 9, then 3, then 0 you don't face that problem.

[DjPal]

Hi
sanjib65

the aim is to move multiple selected items from one listbox to another listbox. i have tried the following code;

private void btnMovell_Click(object sender, EventArgs e)
{
lstBoxl.Items.Add(lstBoxr.Text);
lstBoxr.Items.Remove(lstBoxr.SelectedItems);


but it just moves one selected item at a time.

[tlhintoq]

the aim is to move multiple selected items from one listbox to another listbox. i have tried the following code;

You are not listening to the advice being given you.

You have to go through the ListBox.Items collection in a loop and move the specific items one at a time.

MSDN On the ListBox.SelectedIndexCollection

[DjPal]

sorry im new to programming and dont understand it. im not purposely ignoring advice!

[sanjib65]

Try this

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
 
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            listBox1.Items.AddRange(new String[] { "Item1", "Item2", "Item3", "Item4" });
        }
 
 
        private void button1_Click(object sender, EventArgs e)
        {
 
            foreach (int i in listBox1.SelectedIndices)
            {
                listBox2.Items.Add(listBox1.Items[i].ToString());                
            }
        }
    }
}
 
 

What I've done is very simple. Adding 4 Items in listBox1 first, so that when the form opens up listBox1 is full. Now selecting all Items just clicking the button I move all items at once to listBox2.

[DjPal]

@sanjib65
hi sanjib65,

brilliant! now everything i select is copied to the other listbox, but its not a 'move' since the items in the original listbox are still there after the move.

so i modified the code as below but, all the items don't get removed! strange.

private void btnMoverr_Click(object sender, EventArgs e)
{
foreach (int i in lstBoxl.SelectedIndices)
{
lstBoxr.Items.Add(lstBoxl.Items[i].ToString());
lstBoxl.Items.Remove(lstBoxl.Items[i]);
}
}

Any ideas??

thanks so much for your help.

[tlhintoq]

Any ideas??

Yeah, go back and read the earlier advice telling you to NOT do it that way. First copy everything (in one loop) THEN remove everything selected in REVERSE order (in a second loop) so you don't screw up the indexes of the selected items.

[sanjib65]

What tlhintoq had said earlier is the proper way. You have to go for a second loop in reverse order. For fun I coded this way outside the first loop:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
 
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            listBox1.Items.AddRange(new String[] { "Item1", "Item2", "Item3", "Item4" });
        }
 
 
        private void button1_Click(object sender, EventArgs e)
        {
 
            foreach (int i in listBox1.SelectedIndices)
            {
                listBox2.Items.Add(listBox1.Items[i].ToString());               
            }
            listBox1.Items.Remove(listBox1.Items[3].ToString());
            listBox1.Items.Remove(listBox1.Items[2].ToString());
            listBox1.Items.Remove(listBox1.Items[1].ToString());
            listBox1.Items.Remove(listBox1.Items[0].ToString());
 
 
 
 
 
        }
    }
}
 
 

[DjPal]

Thanks a lot everyone! Managed in the end!

[Jyotsana]

vry nice
vry neatly explained
u may also read this:
Move Items from one ListBox to another in CSharp .NET