Trouble setting the selectedindex of a listbox

[John Kotuby]

Hi all,

I think this should be a very easy thing to do, but I am having difficulty
finding the documentation or maybe just my implementaion is wrong. I fill a
single-select listbox with US State names and Abbreviations.
Here is the code:

If StateTable.Rows.Count > 0 Then
Dim lstValue, lstText As String
lststate.Items.Clear()
For Each row As DataRow In StateTable.Rows
lstValue = row.Item("id").ToString
lstText = row.Item("name").ToString
Me.lststate.Items.Add(New ListItem(lstText, lstValue))
Next
End If
Dim i As Integer
i = lststate.Items.IndexOf(lststate.Items.FindByValue(state))

'Response.Write(CStr(i))
'Response.End()

Me.lststate.SelectedIndex = i

The contents of the variable "state" which I am using for the search is
"CT", a value that definitely exists in the StateTable.
The displayed text is the "name" field from the StateTable. I am assuming
that the value is the "id" because of the way I am populating the listbox.

Me.lststate.Items.Add(New ListItem(lstText, lstValue))

The listbox is definitely populating but the displayed text at the top is
Alaska (the first state in the table).

I am trying to set the Selected Index according to a known state
abbreviation which exists in the listbox. It is correct in the table.
But, my debugging code that displays the value i returned by
lststate.Items.IndexOf(lststate.Items.FindByValue(state))
is always -1.

There must be an easy way to do this, but for the moment I am stumped.
Thanks for any help...

 

[IfThenElse]

Hi,

you sure that the "CT" is the Value

 

[mark4asp]

Hi all,

I think this should be a very easy thing to do, but I am having difficulty
finding the documentation or maybe just my implementaion is wrong. I fill a
single-select listbox with US State names and Abbreviations.
Here is the code:

If StateTable.Rows.Count > 0 Then
Dim lstValue, lstText As String
lststate.Items.Clear()
For Each row As DataRow In StateTable.Rows
lstValue = row.Item("id").ToString
lstText = row.Item("name").ToString
Me.lststate.Items.Add(New ListItem(lstText, lstValue))
Next
End If
Dim i As Integer
i = lststate.Items.IndexOf(lststate.Items.FindByValue(state))

'Response.Write(CStr(i))
'Response.End()

Me.lststate.SelectedIndex = i

The contents of the variable "state" which I am using for the search is
"CT", a value that definitely exists in the StateTable.
The displayed text is the "name" field from the StateTable. I am assuming
that the value is the "id" because of the way I am populating the listbox.

Me.lststate.Items.Add(New ListItem(lstText, lstValue))

The listbox is definitely populating but the displayed text at the top is
Alaska (the first state in the table).

I am trying to set the Selected Index according to a known state
abbreviation which exists in the listbox. It is correct in the table.
But, my debugging code that displays the value i returned by
lststate.Items.IndexOf(lststate.Items.FindByValue(state))
is always -1.

There must be an easy way to do this, but for the moment I am stumped.
Thanks for any help...

Are you sure CT is the value is a good question. View your HTML output
(the <options>) to make sure nothing unusual is happening - for
instance, perhaps there are spaces accidentally appended and you need to
trim them? So, perhaps CT is not one of the values? Maybe "CT "
instead. The other thing I'd look for is a missing cast.

Set a break point and debug the code.

PS: Add another condition here
If StateTable.Rows.Count > 0 Then
to check that StateTable is not null. In general, always check that
DataSets and DataTables are not null before you use them.

 

[John Kotuby]

Thanks for the responses guys and also the suggestion to check for
StateTable is NOT NULL.
I presume that by your answers my implementation is fine, since you are both
concentrating on the values.

I will look more closely at all the values...maybe iterate throug both the
table and lisbox contents to make sure there is a match in every case, as
well as checking the value of the "state" variable.

It would be nice to be able to just "set" the SelectedValue. I am wondering
why that more direct route is not available.

 

[Mark Rae [MVP]]

It would be nice to be able to just "set" the SelectedValue. I am
wondering why that more direct route is not available.

lstState.SelectedValue = "CT"

or

lstState.Items.FindByValue("CT").Selected = True

 

[John Kotuby]

Thanks Mark,
I must have misread MSDN doc on that. I thought that only the SelectedIndex
was settable.

Yep there was a dumb mistake on my part. The State abbreviations were coming
from SQL lookup table in a field defined as Char(10) and I wasn't trimming
them. Some days I wonder where my head is.

 

[Mark Rae [MVP]]

I must have misread MSDN doc on that. I thought that only the
SelectedIndex was settable.

Easily done...

Yep there was a dumb mistake on my part. The State abbreviations were
coming from SQL lookup table in a field defined as Char(10) and I wasn't
trimming them. Some days I wonder where my head is.

Are US state abbreviations ever anything other than two characters in
length...?