ListBox Problem

[camainc]

I am adding some objects to a standard list box. When I add multiple
objects, I experience no problems. However, when I add a single object,
I cannot set the SelectedIndex property to 0 - it stays at -1. Does
anyone know why this is happening, and how to work around it?

Sample code:

With lstUsers
.BeginUpdate()
.Items.Clear()
For Each entity As IBusinessEntity In Coll
.Items.Add(entity)
Next
.EndUpdate()
End With

To select the first item in the list:

If lstUsers.Count > 0 Then
lstUsers.SelectedIndex = 0
End If

The above code works fine for multiple objects, but with only one
object the SelectedIndex stays at -1. Setting the SelectedIndex to 0
doesn't throw an exception, but it never changes.

I need some help with this.

Thanks

[Ahmed]

Hi,

I tried your code on both .NET 1.1 and .NET 2.0 except instead of using
objects I used strings and it works fine. First item is selected wether
there is one value or multiple values. Did you try entity.toString? Are
you sure your code compiles? listbox.count is not a valid property. I
am assuming you meant lstUsers.items.count >0
ca*****@gmail.com wrote:

I am adding some objects to a standard list box. When I add multiple
objects, I experience no problems. However, when I add a single object,
I cannot set the SelectedIndex property to 0 - it stays at -1. Does
anyone know why this is happening, and how to work around it?

Sample code:

With lstUsers
.BeginUpdate()
.Items.Clear()
For Each entity As IBusinessEntity In Coll
.Items.Add(entity)
Next
.EndUpdate()
End With

To select the first item in the list:

If lstUsers.Count > 0 Then
lstUsers.SelectedIndex = 0
End If

The above code works fine for multiple objects, but with only one
object the SelectedIndex stays at -1. Setting the SelectedIndex to 0
doesn't throw an exception, but it never changes.

I need some help with this.

Thanks

[camainc]

Thanks for the reply.

I can't use the .ToString method because the objects have properties
and data that I am accessing. It is a really weird problem, but I think
I've found a workaround. When there is only one object in my
collection, I do not call .BeginUpdate() and .EndUpdate().

For some reason, when I do that I am able to programmatically select
the single object in the listbox.
Ahmed wrote:

Hi,

I tried your code on both .NET 1.1 and .NET 2.0 except instead of using
objects I used strings and it works fine. First item is selected wether
there is one value or multiple values. Did you try entity.toString? Are
you sure your code compiles? listbox.count is not a valid property. I
am assuming you meant lstUsers.items.count >0
ca*****@gmail.com wrote:

I am adding some objects to a standard list box. When I add multiple
objects, I experience no problems. However, when I add a single object,
I cannot set the SelectedIndex property to 0 - it stays at -1. Does
anyone know why this is happening, and how to work around it?

Sample code:

With lstUsers
.BeginUpdate()
.Items.Clear()
For Each entity As IBusinessEntity In Coll
.Items.Add(entity)
Next
.EndUpdate()
End With

To select the first item in the list:

If lstUsers.Count > 0 Then
lstUsers.SelectedIndex = 0
End If

The above code works fine for multiple objects, but with only one
object the SelectedIndex stays at -1. Setting the SelectedIndex to 0
doesn't throw an exception, but it never changes.

I need some help with this.

Thanks

[Ahmed]

I am glad you found a work around for the problem. I just tried your
code with object this time and it also worked fine. Are you sure that:

lstUsers.SelectedIndex = 0
is being executed?

ca*****@gmail.com wrote:

Thanks for the reply.

I can't use the .ToString method because the objects have properties
and data that I am accessing. It is a really weird problem, but I think
I've found a workaround. When there is only one object in my
collection, I do not call .BeginUpdate() and .EndUpdate().

For some reason, when I do that I am able to programmatically select
the single object in the listbox.
Ahmed wrote:

Hi,

I tried your code on both .NET 1.1 and .NET 2.0 except instead of using
objects I used strings and it works fine. First item is selected wether
there is one value or multiple values. Did you try entity.toString? Are
you sure your code compiles? listbox.count is not a valid property. I
am assuming you meant lstUsers.items.count >0
ca*****@gmail.com wrote:

I am adding some objects to a standard list box. When I add multiple
objects, I experience no problems. However, when I add a single object,
I cannot set the SelectedIndex property to 0 - it stays at -1. Does
anyone know why this is happening, and how to work around it?

Sample code:

With lstUsers
.BeginUpdate()
.Items.Clear()
For Each entity As IBusinessEntity In Coll
.Items.Add(entity)
Next
.EndUpdate()
End With

To select the first item in the list:

If lstUsers.Count > 0 Then
lstUsers.SelectedIndex = 0
End If

The above code works fine for multiple objects, but with only one
object the SelectedIndex stays at -1. Setting the SelectedIndex to 0
doesn't throw an exception, but it never changes.

I need some help with this.

Thanks

[camainc]

Yep. I worked with it for quite awhile, trying this and that, until I
came upon the solution above. I think there must be something going on
with object references behind the scenes that I'm just not seeing.

Thanks for your interest.

Ahmed wrote:

I am glad you found a work around for the problem. I just tried your
code with object this time and it also worked fine. Are you sure that:

lstUsers.SelectedIndex = 0
is being executed?

ca*****@gmail.com wrote:

Thanks for the reply.

I can't use the .ToString method because the objects have properties
and data that I am accessing. It is a really weird problem, but I think
I've found a workaround. When there is only one object in my
collection, I do not call .BeginUpdate() and .EndUpdate().

For some reason, when I do that I am able to programmatically select
the single object in the listbox.
Ahmed wrote:

Hi,

I tried your code on both .NET 1.1 and .NET 2.0 except instead of using
objects I used strings and it works fine. First item is selected wether
there is one value or multiple values. Did you try entity.toString? Are
you sure your code compiles? listbox.count is not a valid property. I
am assuming you meant lstUsers.items.count >0
ca*****@gmail.com wrote:
> I am adding some objects to a standard list box. When I add multiple
> objects, I experience no problems. However, when I add a single object,
> I cannot set the SelectedIndex property to 0 - it stays at -1. Does
> anyone know why this is happening, and how to work around it?
>
> Sample code:
>
> With lstUsers
> .BeginUpdate()
> .Items.Clear()
> For Each entity As IBusinessEntity In Coll
> .Items.Add(entity)
> Next
> .EndUpdate()
> End With
>
> To select the first item in the list:
>
> If lstUsers.Count > 0 Then
> lstUsers.SelectedIndex = 0
> End If
>
> The above code works fine for multiple objects, but with only one
> object the SelectedIndex stays at -1. Setting the SelectedIndex to 0
> doesn't throw an exception, but it never changes.
>
> I need some help with this.
>
> Thanks