Avoid duplicate items in listbox 2

[clanm]

I have two list boxes. The one of the left has available numbers, and the right is what the user will build for "selected" numbers.
I can pull them over to the right "selected" side, and allow users to delete them from the right if they make a mistake.

What I want to do is NOT allow users to add duplicate values on the right side.

Any suggestions?

Thanks!

 

[jbenson001]

        Dim li As New ListItem
        For Each li In ListBox1.Items
            If li.Selected = True Then
                If Not ListBox2.Items.Contains(li) Then
                    ListBox2.Items.Add(li)
                End If
            End If
        Next

Jim

 

[clanm]

Awesome! Thanks Jim!

 

[jbenson001]

You're welcome..glad it helps you.

Jim

 

[clanm]

Hello!

I used this code, and it works to not allow duplicates if I stay on the selected item in the list box and try to click it multiple times:

Dim li As New ListItem
For Each li In LB1.Items
If li.Selected = True Then
If Not ListBox2.Items.Contains(li) Then
ListBox2.Items.Add(li)
End If
End If
Next

If I go to another list item, say the one directly below, the go back to the initial item, I can in fact add duplicates. Any ideas? I'll keep searching too.

Thanks!

 

[jbenson001]

It is working perfectly for me. It should not allow it to add if it is already in the list. I have tested it many times.

Let me know what you find.

 

[clanm]

jbenson001,

It would help if I put the right code in the correct listbox.

My fault...you're 100% right...it works fine. I had to set the mode to multiple select.

thanks again!

 

[clanm]

jbenson001,

Any ideas on how to get the items ASC orded when they're added? I'll keep looking.

Thanks again for the help!

 

[ca8msm]

If you use an Array to store the item's values, then you can use the Sort method of the Array and then bind it to the ListBox.


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[clanm]

ca8msm,

I was just looking into a SortedList.....

I'll try that too!

thanks!

 

[clanm]

ca8msm,

If I click on a second item to add it to my listbox, ListBox2, I get an error of:
At least one object must implement IComparable

Here's the code:

'Sort items ASC
Dim item As String
Dim items As New ArrayList(ListBox2.Items)
Dim x As Integer
For x = 0 To items.Count - 1
'step through the arraylist, one at a time & create string
item += items(x).ToString & ","
items.Sort()
Next

 

[ca8msm]

You only need to call the Sort method once if you are using an ArrayList e.g.

http://msdn2.microsoft.com/en-us/library/8k6e334t.aspx

____________________________________________________________

Need help finding an answer?

Try the Search Facility or read FAQ222-2244 on how to get better results.

 

[clanm]

ca8msm,

I'm trying this code but get:
At least one object must implement IComparable.

Dim items As New ArrayList(ListBox2.Items)
items.Sort()
ListBox2.DataSource = items

 

[clanm]

Got it to work with this:

http://www.411asp.net/func/content?...ific/web/userinte/webcontr/listbox&id=5881410

Thanks to all for the help!

 

[jbenson001]

glad you got it working ..and good example.. will have to keep that one on file

JIm