Thread: Remove Duplicate Items

Hey i am trying to remove duplicate items from 2 listboxes.... i have the code to remove duplicate items from one list box...i'm trying to build a database of names and i dont want the names to be on there twice. So I'm wanting one list to be the database or names and the other list to be new names.. Lets say i have the database list that has 1,000 names and the other list has 200 names...I want to have a button that when it is clicked it will remove any names from the second list if it is already in the database list....here is the code i have to remove duplicates

Public Sub RemoveDuplicateItem(ByVal listboxName As ListBox)
listboxName.Sorted = True
listboxName.Refresh()
Dim index As Integer
Dim itemcount As Integer = listboxName.Items.Count

If itemcount > 1 Then
Dim lastitem As String = listboxName.Items(itemcount - 1)

For index = itemcount - 2 To 0 Step -1
If listboxName.Items(index) = lastitem Then
listboxName.Items.RemoveAt(index)
Else
lastitem = listboxName.Items(index)
End If
Next
End If
End Sub

Any suggestions or a better way to do this?

Get rid of that removeduplicates sub. All you need to do to remove duplicates is to add a couple lines to the code that you're using to load the list.

For example:

if listbox1.items.contains(strItem) = false then
listbox1.items.add(strItem)
end if

It's basically saying if the list doesn't already contain strItem then add it.

Post the code you're using to load the list in the first place and I'll modify it to work as you need it to.

It's better to prevent adding duplicates to listbox than removing it later.

he has them added already