Listbox bug ??

[Steve Cutting]

Hi all,

I have found that when I have a listbox bound to a datatable, the
ClearSelected method of the listbox does not work properly. It just changes
the selection to item 1 in the listbox. Calling ClearSelected again then
removes the selection.

If the listbox is unbound it works correctly. ie only one call of
ClearSelected is required.

I have tried using listbox.selectedindex = -1
This has the same effect.

Anyone else encountered this ??
Steve

[Cor Ligthert]

Steve,

I am not sure however it seems one of the very well known bugs.
Did you try setting the selectedindex twice to -1 that is mostly the
solution.

I hope this helps,

Cor

I have found that when I have a listbox bound to a datatable, the
ClearSelected method of the listbox does not work properly. It just changes the selection to item 1 in the listbox. Calling ClearSelected again then
removes the selection.

If the listbox is unbound it works correctly. ie only one call of
ClearSelected is required.

I have tried using listbox.selectedindex = -1
This has the same effect.

Anyone else encountered this ??
Steve

[Steve Cutting]

On Sat, 14 Aug 2004 12:46:44 +0200, "Cor Ligthert" <no**********@planet.nl>
wrote:

Steve,

I am not sure however it seems one of the very well known bugs.
Did you try setting the selectedindex twice to -1 that is mostly the
solution.

Hi Cor,

Yes both options work if I call them twice. (ie either clearselected, or
..selectedindex=-1). The trouble is it only seems to work once the listbox is
visible.

I have a modal dialog form where I want the selection cleared when the form
is displayed. The above method in my form_load event works for the initial
..showdialog call of the form after it's instantiation, but not after the
form has been hidden by dialogOK/cancel and then called again with
..showdialog. On subsequent calls the first list item is always selected
(even if there was nothing selected when it was closed).

I suppose one option would be to just .dispose the form after each call and
recreate it each time I need it, seeing as it works on the first call.

thanks
Steve

[Cor Ligthert]

Steve,

Probably you have your code in the load event.
Can you bring that to the New Sub after there where is written.
'Add any initialization after the InitializeComponent() call

I tried it, and than it works for me, in the load event I get the same
problem as you.

I hope this helps?

Cor

On Sat, 14 Aug 2004 12:46:44 +0200, "Cor Ligthert" <no**********@planet.nl> wrote:

Steve,

I am not sure however it seems one of the very well known bugs.
Did you try setting the selectedindex twice to -1 that is mostly the
solution.
Hi Cor,

Yes both options work if I call them twice. (ie either clearselected, or
.selectedindex=-1). The trouble is it only seems to work once the listbox

is visible.

I have a modal dialog form where I want the selection cleared when the form is displayed. The above method in my form_load event works for the initial
.showdialog call of the form after it's instantiation, but not after the
form has been hidden by dialogOK/cancel and then called again with
.showdialog. On subsequent calls the first list item is always selected
(even if there was nothing selected when it was closed).

I suppose one option would be to just .dispose the form after each call and recreate it each time I need it, seeing as it works on the first call.

thanks
Steve

[Steve Cutting]

On Sat, 14 Aug 2004 13:54:44 +0200, "Cor Ligthert" <no**********@planet.nl>
wrote:

Steve,

Probably you have your code in the load event.
Can you bring that to the New Sub after there where is written.
'Add any initialization after the InitializeComponent() call

I tried it, and than it works for me, in the load event I get the same
problem as you.

I hope this helps?

Hi Cor,

What I have at the moment:

1. In the New sub I call my InitTable sub, which creates columns in the
datatable and then binds the listbox to it.

2. In my form_load I call a function which populates the datatable with data
from a database. Having this in the form_load means the data is refreshed
every time the form is called with .showdialog.

3. After this I have put my .selectedindex = -1 in the form_load

As I said before this works for the first call but not subsequent ones.

I just tried putting all of the above in my New sub and now it doesn't work
even for the first call. Item 1 is selected, even with 2 x .selectedindex=-1
and 2 x clearselected in the New sub after I populate the datatable.
thanks
Steve

[Herfried K. Wagner [MVP]]

* Steve Cutting <sc******@optusnet.com.au> scripsit:

I have found that when I have a listbox bound to a datatable, the
ClearSelected method of the listbox does not work properly. It just changes
the selection to item 1 in the listbox. Calling ClearSelected again then
removes the selection.

If the listbox is unbound it works correctly. ie only one call of
ClearSelected is required.

I have tried using listbox.selectedindex = -1
This has the same effect.

BUG: ComboBox Does Not Clear When You Set SelectedIndex to -1
<URL:http://support.microsoft.com/?scid=kb;EN-US;327244>

--
Herfried K. Wagner [MVP]
<URL:http://dotnet.mvps.org/>

[Steve Cutting]

On 14 Aug 2004 15:01:56 +0200, hi***************@gmx.at (Herfried K. Wagner
[MVP]) wrote:

* Steve Cutting <sc******@optusnet.com.au> scripsit:

I have found that when I have a listbox bound to a datatable, the
ClearSelected method of the listbox does not work properly. It just changes
the selection to item 1 in the listbox. Calling ClearSelected again then
removes the selection.

If the listbox is unbound it works correctly. ie only one call of
ClearSelected is required.

I have tried using listbox.selectedindex = -1
This has the same effect.

BUG: ComboBox Does Not Clear When You Set SelectedIndex to -1
<URL:http://support.microsoft.com/?scid=kb;EN-US;327244>

Thanks Herfied. Didn't realise it affected the combo-box too. I was talking
about the listbox

Steve

[Cor Ligthert]

Steve,

Do you want to select the first item or want you keep it as it was, you
confuse me, because from your previous message I understood that you did
want to keep it in the state you left it?

Cor

[Steve Cutting]

On Sat, 14 Aug 2004 15:18:53 +0200, "Cor Ligthert" <no**********@planet.nl>
wrote:

Steve,

Do you want to select the first item or want you keep it as it was, you
confuse me, because from your previous message I understood that you did
want to keep it in the state you left it?

Hi Cor,

I want nothing to be selected in the listbox whenever I call the form with
..showdialog

thanks
Steve

[Herfried K. Wagner [MVP]]

* Steve Cutting <sc******@optusnet.com.au> scripsit:

I have tried using listbox.selectedindex = -1
This has the same effect.

BUG: ComboBox Does Not Clear When You Set SelectedIndex to -1
<URL:http://support.microsoft.com/?scid=kb;EN-US;327244>

Thanks Herfied. Didn't realise it affected the combo-box too. I was talking
about the listbox

I assume it's the same bug.

--
Herfried K. Wagner [MVP]
<URL:http://dotnet.mvps.org/>

[Cor Ligthert]

Steve,

This works without any problem for me.

Private Sub Form2_Activated(ByVal sender _
As Object, ByVal e As System.EventArgs) Handles MyBase.Activated
Me.ListBox1.SelectedIndex = -1
End Sub

When it does not for you, reply than I past in the test I made.

Cor

[Steve Cutting]

On Sat, 14 Aug 2004 15:31:12 +0200, "Cor Ligthert" <no**********@planet.nl>
wrote:

Steve,

This works without any problem for me.

Private Sub Form2_Activated(ByVal sender _
As Object, ByVal e As System.EventArgs) Handles MyBase.Activated
Me.ListBox1.SelectedIndex = -1
End Sub

Thanks Cor. That works :) Using clearselected works there too.

thanks again for your help
Steve

[Cor Ligthert]

Herfried,

I was assuming that as well in my first message.
However is that not that combobox textbox part?

:-)

Cor

[Herfried K. Wagner [MVP]]

* "Cor Ligthert" <no**********@planet.nl> scripsit:

I was assuming that as well in my first message.
However is that not that combobox textbox part?

Maybe it's a bug in the underlying 'ListControl' implementation that is
used by both, comboboxes and listboxes.

--
Herfried K. Wagner [MVP]
<URL:http://dotnet.mvps.org/>