Error Using SelectedIndices of Listbox with custom objects

[Alex Stevens]

I'd already posted this in microsoft.publi c.dotnet.framew ork.windowsform s
and microsoft.publi c.dotnet.framew ork.windowsform s.controls to no avail so
apologies for the cross-posting.

Hi,

I'm writing a usercontrol which displays the typical two listboxes and the
ability to move items from one to the other.

The listboxes are populated with my custom objects (SwapItem), which simply
have a ValueMember, DisplayMember a couple of other properties and the
tostring function to display the DisplayMember in the listbox.

The issue I'm getting is with the SelectedIndices array
I selected four items in the listbox and then I use:

For i As Int32 = 0 To lstAvailable.Se lectedIndices.C ount - 1
lstItem =
CType(lstAvaila ble.Items.Item( lstAvailable.Se lectedIndices(i )),
SwapListBoxItem )
lstItem.Selecte d = True
intIndex = i
Next

Before execution gets to this, the lstAvailable.Se lectedIndices.c ount
returns 4.
Happy Days.

However when I try to evaluate lstAvailable.Se lectedIndices(0 ) or
lstAvailable.Se lectedIndices(1 ) or lstAvailable.Se lectedIndices(2 ) or
lstAvailable.Se lectedIndices(4 ) i get the error "Index was outside the
bounds of the array".
This can't be true as the.count is 4.

I get exactly the same results using the SelectedItems array to.
Is this a symptom of using my own custom object in the listbox (I've posted
the custom object code below for reference)??

Once the custom object is instantiated and then populated I use this line to
add it to the listbox:
lstAvailable.It ems.Add(SwapIte m)

Also, when I use:
Dim lst As SwapListBoxItem
For Each lst In lstAvailable.Se lectedItems
lstItem.Selecte d = True
Next

The lstAvailable.Se lectedItems.Cou nt returns 4, but the execution doesn't
iterate, just jumps over the For statement.
However, I can use this and it iterates correctly:

Dim lstItem As SwapListBoxItem
For Each lstItem In lstSelected.Ite ms
lstItem.Selecte d = True
Next

So it seems that the items collection can iterate my customer objects but
the selecteditems cannot????

Thanks

Alex

*****Custom Object Code Start******
Public Class SwapListBoxItem

Private m_objValueMembe r As Object = ""
Private m_strDisplayMem ber As String = ""
Private m_bolSelected As Boolean = False

Public Property ValueMember() As Object
Get
Return m_objValueMembe r
End Get
Set(ByVal ValueMember As Object)
m_objValueMembe r = ValueMember
End Set
End Property

Public Property DisplayMember() As String
Get
Return m_strDisplayMem ber
End Get
Set(ByVal DisplayMember As String)
m_strDisplayMem ber = DisplayMember
End Set
End Property

Public Property Selected() As Boolean
Get
Return m_bolSelected
End Get
Set(ByVal Selected As Boolean)
m_bolSelected = Selected
End Set
End Property

Public Sub ChangeSelected( )
m_bolSelected = Not m_bolSelected
End Sub

Public Overrides Function ToString() As String
Return Me.DisplayMembe r
End Function

End Class

*****Custom Object Code End******

[One Handed Man \( OHM#\)]

Remember, you are returning a collection of indicies so you should use the
follwing to access a particular element

ListBox1.Select edIndicies.Item ( numOfElement )

OHM

"Alex Stevens" <Al************ **********@gcc. co.uk> wrote in message
news:eU******** ******@TK2MSFTN GP09.phx.gbl...

I'd already posted this in microsoft.publi c.dotnet.framew ork.windowsform s
and microsoft.publi c.dotnet.framew ork.windowsform s.controls to no avail so
apologies for the cross-posting.

Hi,

I'm writing a usercontrol which displays the typical two listboxes and the
ability to move items from one to the other.

The listboxes are populated with my custom objects (SwapItem), which simply have a ValueMember, DisplayMember a couple of other properties and the
tostring function to display the DisplayMember in the listbox.

The issue I'm getting is with the SelectedIndices array
I selected four items in the listbox and then I use:

For i As Int32 = 0 To lstAvailable.Se lectedIndices.C ount - 1
lstItem =
CType(lstAvaila ble.Items.Item( lstAvailable.Se lectedIndices(i )),
SwapListBoxItem )
lstItem.Selecte d = True
intIndex = i
Next

Before execution gets to this, the lstAvailable.Se lectedIndices.c ount
returns 4.
Happy Days.

However when I try to evaluate lstAvailable.Se lectedIndices(0 ) or
lstAvailable.Se lectedIndices(1 ) or lstAvailable.Se lectedIndices(2 ) or
lstAvailable.Se lectedIndices(4 ) i get the error "Index was outside the
bounds of the array".
This can't be true as the.count is 4.

I get exactly the same results using the SelectedItems array to.
Is this a symptom of using my own custom object in the listbox (I've posted the custom object code below for reference)??

Once the custom object is instantiated and then populated I use this line to add it to the listbox:
lstAvailable.It ems.Add(SwapIte m)

Also, when I use:
Dim lst As SwapListBoxItem
For Each lst In lstAvailable.Se lectedItems
lstItem.Selecte d = True
Next

The lstAvailable.Se lectedItems.Cou nt returns 4, but the execution doesn't
iterate, just jumps over the For statement.
However, I can use this and it iterates correctly:

Dim lstItem As SwapListBoxItem
For Each lstItem In lstSelected.Ite ms
lstItem.Selecte d = True
Next

So it seems that the items collection can iterate my customer objects but
the selecteditems cannot????

Thanks

Alex

*****Custom Object Code Start******
Public Class SwapListBoxItem

Private m_objValueMembe r As Object = ""
Private m_strDisplayMem ber As String = ""
Private m_bolSelected As Boolean = False

Public Property ValueMember() As Object
Get
Return m_objValueMembe r
End Get
Set(ByVal ValueMember As Object)
m_objValueMembe r = ValueMember
End Set
End Property

Public Property DisplayMember() As String
Get
Return m_strDisplayMem ber
End Get
Set(ByVal DisplayMember As String)
m_strDisplayMem ber = DisplayMember
End Set
End Property

Public Property Selected() As Boolean
Get
Return m_bolSelected
End Get
Set(ByVal Selected As Boolean)
m_bolSelected = Selected
End Set
End Property

Public Sub ChangeSelected( )
m_bolSelected = Not m_bolSelected
End Sub

Public Overrides Function ToString() As String
Return Me.DisplayMembe r
End Function

End Class

*****Custom Object Code End******

[Alex Stevens]

Well, that was irritating..... ..

I copied the code into a new project to attach to this message.
Added a new listbox to a new form and hooked up the code.

Guess what....it worked.

I then gradually worked back to the original form (which is actually a
custom control), and ended up simply deleting the listbox on the control,
and adding a new one and renaming it.

Guess what it started to work again.
(I wondered why there weren't many posting with the same syptoms).

Also, lstAvailable.Se lectedIndices(i ) works just the same as
lstAvailable.Se lectedIndices.I tem(i)

I wish I could invoice MS for what was a day or so of my time!!!
"One Handed Man ( OHM#)" <news.microsoft .com> wrote in message
news:ug******** ********@TK2MSF TNGP10.phx.gbl. ..

Remember, you are returning a collection of indicies so you should use the
follwing to access a particular element

ListBox1.Select edIndicies.Item ( numOfElement )

OHM

"Alex Stevens" <Al************ **********@gcc. co.uk> wrote in message
news:eU******** ******@TK2MSFTN GP09.phx.gbl...

I'd already posted this in microsoft.publi c.dotnet.framew ork.windowsform s and microsoft.publi c.dotnet.framew ork.windowsform s.controls to no avail so apologies for the cross-posting.

Hi,

I'm writing a usercontrol which displays the typical two listboxes and the ability to move items from one to the other.

The listboxes are populated with my custom objects (SwapItem), which simply

have a ValueMember, DisplayMember a couple of other properties and the
tostring function to display the DisplayMember in the listbox.

The issue I'm getting is with the SelectedIndices array
I selected four items in the listbox and then I use:

For i As Int32 = 0 To lstAvailable.Se lectedIndices.C ount - 1
lstItem =
CType(lstAvaila ble.Items.Item( lstAvailable.Se lectedIndices(i )),
SwapListBoxItem )
lstItem.Selecte d = True
intIndex = i
Next

Before execution gets to this, the lstAvailable.Se lectedIndices.c ount
returns 4.
Happy Days.

However when I try to evaluate lstAvailable.Se lectedIndices(0 ) or
lstAvailable.Se lectedIndices(1 ) or lstAvailable.Se lectedIndices(2 ) or
lstAvailable.Se lectedIndices(4 ) i get the error "Index was outside the
bounds of the array".
This can't be true as the.count is 4.

I get exactly the same results using the SelectedItems array to.
Is this a symptom of using my own custom object in the listbox (I've

posted

the custom object code below for reference)??

Once the custom object is instantiated and then populated I use this line to

add it to the listbox:
lstAvailable.It ems.Add(SwapIte m)

Also, when I use:
Dim lst As SwapListBoxItem
For Each lst In lstAvailable.Se lectedItems
lstItem.Selecte d = True
Next

The lstAvailable.Se lectedItems.Cou nt returns 4, but the execution

doesn't iterate, just jumps over the For statement.
However, I can use this and it iterates correctly:

Dim lstItem As SwapListBoxItem
For Each lstItem In lstSelected.Ite ms
lstItem.Selecte d = True
Next

So it seems that the items collection can iterate my customer objects but the selecteditems cannot????

Thanks

Alex

*****Custom Object Code Start******
Public Class SwapListBoxItem

Private m_objValueMembe r As Object = ""
Private m_strDisplayMem ber As String = ""
Private m_bolSelected As Boolean = False

Public Property ValueMember() As Object
Get
Return m_objValueMembe r
End Get
Set(ByVal ValueMember As Object)
m_objValueMembe r = ValueMember
End Set
End Property

Public Property DisplayMember() As String
Get
Return m_strDisplayMem ber
End Get
Set(ByVal DisplayMember As String)
m_strDisplayMem ber = DisplayMember
End Set
End Property

Public Property Selected() As Boolean
Get
Return m_bolSelected
End Get
Set(ByVal Selected As Boolean)
m_bolSelected = Selected
End Set
End Property

Public Sub ChangeSelected( )
m_bolSelected = Not m_bolSelected
End Sub

Public Overrides Function ToString() As String
Return Me.DisplayMembe r
End Function

End Class

*****Custom Object Code End******

[One Handed Man \( OHM#\)]

Actually, I tested this and got the same error, it was only when I used
..Item that it worked consistantly, I found Once I had encountered the error
once, I ket getting it by omitting the .Item

One would think that Item would be the default property to enable you to use
parenthasis directly after the object, but I had to consistently use item
for good results.

Regards - OHM
"Alex Stevens" <Al************ **********@gcc. co.uk> wrote in message
news:%2******** *******@TK2MSFT NGP10.phx.gbl.. .

Well, that was irritating..... ..

I copied the code into a new project to attach to this message.
Added a new listbox to a new form and hooked up the code.

Guess what....it worked.

I then gradually worked back to the original form (which is actually a
custom control), and ended up simply deleting the listbox on the control,
and adding a new one and renaming it.

Guess what it started to work again.
(I wondered why there weren't many posting with the same syptoms).

Also, lstAvailable.Se lectedIndices(i ) works just the same as
lstAvailable.Se lectedIndices.I tem(i)

I wish I could invoice MS for what was a day or so of my time!!!
"One Handed Man ( OHM#)" <news.microsoft .com> wrote in message
news:ug******** ********@TK2MSF TNGP10.phx.gbl. ..

Remember, you are returning a collection of indicies so you should use the

follwing to access a particular element

ListBox1.Select edIndicies.Item ( numOfElement )

OHM

"Alex Stevens" <Al************ **********@gcc. co.uk> wrote in message
news:eU******** ******@TK2MSFTN GP09.phx.gbl...

I'd already posted this in

microsoft.publi c.dotnet.framew ork.windowsform s and microsoft.publi c.dotnet.framew ork.windowsform s.controls to no

avail so apologies for the cross-posting.

Hi,

I'm writing a usercontrol which displays the typical two listboxes and the ability to move items from one to the other.

The listboxes are populated with my custom objects (SwapItem), which

simply

have a ValueMember, DisplayMember a couple of other properties and the
tostring function to display the DisplayMember in the listbox.

The issue I'm getting is with the SelectedIndices array
I selected four items in the listbox and then I use:

For i As Int32 = 0 To lstAvailable.Se lectedIndices.C ount - 1
lstItem =
CType(lstAvaila ble.Items.Item( lstAvailable.Se lectedIndices(i )),
SwapListBoxItem )
lstItem.Selecte d = True
intIndex = i
Next

Before execution gets to this, the lstAvailable.Se lectedIndices.c ount
returns 4.
Happy Days.

However when I try to evaluate lstAvailable.Se lectedIndices(0 ) or
lstAvailable.Se lectedIndices(1 ) or lstAvailable.Se lectedIndices(2 ) or
lstAvailable.Se lectedIndices(4 ) i get the error "Index was outside the
bounds of the array".
This can't be true as the.count is 4.

I get exactly the same results using the SelectedItems array to.
Is this a symptom of using my own custom object in the listbox (I've

posted

the custom object code below for reference)??

Once the custom object is instantiated and then populated I use this line

to

add it to the listbox:
lstAvailable.It ems.Add(SwapIte m)

Also, when I use:
Dim lst As SwapListBoxItem
For Each lst In lstAvailable.Se lectedItems
lstItem.Selecte d = True
Next

The lstAvailable.Se lectedItems.Cou nt returns 4, but the execution

doesn't iterate, just jumps over the For statement.
However, I can use this and it iterates correctly:

Dim lstItem As SwapListBoxItem
For Each lstItem In lstSelected.Ite ms
lstItem.Selecte d = True
Next

So it seems that the items collection can iterate my customer objects but the selecteditems cannot????

Thanks

Alex

*****Custom Object Code Start******
Public Class SwapListBoxItem

Private m_objValueMembe r As Object = ""
Private m_strDisplayMem ber As String = ""
Private m_bolSelected As Boolean = False

Public Property ValueMember() As Object
Get
Return m_objValueMembe r
End Get
Set(ByVal ValueMember As Object)
m_objValueMembe r = ValueMember
End Set
End Property

Public Property DisplayMember() As String
Get
Return m_strDisplayMem ber
End Get
Set(ByVal DisplayMember As String)
m_strDisplayMem ber = DisplayMember
End Set
End Property

Public Property Selected() As Boolean
Get
Return m_bolSelected
End Get
Set(ByVal Selected As Boolean)
m_bolSelected = Selected
End Set
End Property

Public Sub ChangeSelected( )
m_bolSelected = Not m_bolSelected
End Sub

Public Overrides Function ToString() As String
Return Me.DisplayMembe r
End Function

End Class

*****Custom Object Code End******