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Two List Box (to Add & remove items )

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4 replies

by thakker123

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Hello
i have to findout what is wrong in this syntex
i have 2 list box
user can select multiple items and click on Cmdadd then that item is to add in list2 & also get remove from list1

below is the syntex

Private Sub CmdRem_Click()
If List2.SelCount = 1 Then
List1.AddItem List2.List(List2.ListIndex)
List2.RemoveItem List2.ListIndex
ElseIf List2.SelCount > 1 Then
Dim b
b = (List2.ListCount - 1)
For a = 0 To b
If List2.Selected(a) = True Then
List1.AddItem List2.List(List2.ListIndex)
List2.RemoveItem List2.ListIndex
End If
Next
Else
MsgBox "Please select the item to remove from savein box"
End If
End Sub

Thanks
athakker

4 replies

by madestroitsolutions

My dear friend, the error is quite simple, and lies on the multiple selection condition:
you are running a for loop that is going to go from a = to b (b being the list count) correct?
Now, if you remove an item during the loop, you think b is still an accurate list count???
Of course not, the listcount is now equal to (b-1), so what you have to do is substract 1 from b every time you delete an item.
NOW HERE IS THE INTERESTING PART:

Even when you substract 1 from b, the iterator still runs up to the original count. I have no idea why, either you cannot change the end value for the iterator, or YOU JUST FOUND A BUG IN VB!, he he..... I reproduced the error you were having, but even after fixing it to run properly, I found out that the for loop would still allow the operations to be executed even when the condition met!.... I could not believe what I was seeing.... the iterator is still going into the instructions although the
comparison returns positive.
Anyways, to make a long story short, don't use the stupid for loop. Use a while wend instead. Here is the code (tested, works 100%):

b = (List2.ListCount - 1)
a = 0
While a <= b
If List2.Selected(a) = True Then
List1.AddItem List2.List(a)
List2.RemoveItem a
List2.Refresh
Debug.Print "Removed item"
b = b - 1
a = -1
End If
a = a + 1
Wend

Put this code instead of the code in the [elseif list2.selcount - 1] then section.

Good luck!

by madestroitsolutions

I forgot to remove the debug.print line, just take it out, unless you want to see how it runs.
Questions or comments? feel free to drop a line at juanr@akaconsulting.com
cya!

by thakker123

Thanks for ur reply,
I have tried Private Sub CmdAdd_Click()
If List1.SelCount = 1 Then
List2.AddItem List1.List(List1.ListIndex)
List1.RemoveItem List1.ListIndex
ElseIf List1.SelCount > 1 Then
Dim a, b
b = (List1.ListCount - 1)
MsgBox " B(ListCount) = " & b
For a = b To 0 Step -1
If List1.Selected(a) = True Then
List1.ListIndex = a
List2.AddItem List1.List(List1.ListIndex)
List1.RemoveItem List1.ListIndex End If
Next
ElseIf List1.SelCount = 0 Then
MsgBox "Please Select the section"
List1.SetFocus
End If
End Sub

Private Sub CmdClr_Click()
Dim b, a
b = (List2.ListCount - 1)
For a = b To 0 Step -1
List2.ListIndex =a
List1.AddItem List2.List(a)
List2.RemoveItem List2.ListIndex
Next
End Sub

Private Sub CmdRem_Click()
If List2.SelCount = 1 Then
List1.AddItem List2.List(List2.ListIndex)
List2.RemoveItem List2.ListIndex
ElseIf List2.SelCount > 1 Then
Dim b, a
b = (List2.ListCount - 1)
For a = b To 0 Step -1
If List2.Selected(a) = True Then
List2.ListIndex = a
List1.AddItem List2.List(List2.ListIndex)
List2.RemoveItem List2.ListIndex
EndIf
Next
Else
MsgBox "Please select the item to remove from savein box"
End If
End Subwith the following code & this works successfully

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