473,416 Members | 1,572 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,416 software developers and data experts.

Programatically changing value of databound combobox

I posted this in dotnet.languages.vb.controls but thought I'd post here as
well..
I have a combobox that is bound to a dataview generated from a dataset.

The dataset has a single table (called "Data") with two columns "Id" and
"Description". Id contains a code and description contains the
description that is displayed in the combobox.

The dataview is generated from the dataset using dv =
ds.Tables("Data").DefaultView.

The Combobox is bound using :

txtLookup.DataSource = dv
txtLookup.ValueMember = "Id"

txtLookup.DisplayMember = "Description"

This works fine, I can read the current "Id" from the combobox using the
txtlookup.selectedvalue property.

However, if I want to programatically set the starting value of the
combobox, I can't seem to work out how to do it. I thought I could just set
the selectedvalue property to any of the vaules of "id" and the combobox
would then display the corresponding description. This appears not to be
the case. I don't know if it is getting confused by the fact that the "Id"
field in the datatable is numeric or if I'm just doing it wrong!

What should I be doing?

Thanks in advance

Simon
Nov 21 '05 #1
7 4543
Combo box index are Zero based and incremental. Your ID column does not have
to correspond with this at all and can be any unique numbers. And yes,
selecting a dropdownlist item is done by setting the SelectedItemIndex to an
appropriate number.
"Simon Verona" <no****@nomail.zzz> wrote in message
news:%2****************@TK2MSFTNGP14.phx.gbl...
I posted this in dotnet.languages.vb.controls but thought I'd post here as
well..
I have a combobox that is bound to a dataview generated from a dataset.

The dataset has a single table (called "Data") with two columns "Id" and
"Description". Id contains a code and description contains the
description that is displayed in the combobox.

The dataview is generated from the dataset using dv =
ds.Tables("Data").DefaultView.

The Combobox is bound using :

txtLookup.DataSource = dv
txtLookup.ValueMember = "Id"

txtLookup.DisplayMember = "Description"

This works fine, I can read the current "Id" from the combobox using the
txtlookup.selectedvalue property.

However, if I want to programatically set the starting value of the
combobox, I can't seem to work out how to do it. I thought I could just
set the selectedvalue property to any of the vaules of "id" and the
combobox would then display the corresponding description. This appears
not to be the case. I don't know if it is getting confused by the fact
that the "Id" field in the datatable is numeric or if I'm just doing it
wrong!

What should I be doing?

Thanks in advance

Simon

Nov 21 '05 #2
But how do I know what the appropriate no is ???

If my datatable has for example:

Id Description
1 Ford
2 Vauxhall
3 Peugeot
6 Ferrari

and I want to set the combobox to "Ferrari" (ie ID=6).. How do I do this?

I'm trying to do : txtlookup.selectedvalue="6" but this isn't doing
what I expect!

I presume that the selecteditemindex property is an offset through the
datatable. Do I have to scan through the datatable counting how far through
the record I want actually is? Will it matter that I've set the combobox
to sort by Description??

Regards
Simon
"Mr Newbie" <he**@now.com> wrote in message
news:OP*************@TK2MSFTNGP11.phx.gbl...
Combo box index are Zero based and incremental. Your ID column does not
have to correspond with this at all and can be any unique numbers. And
yes, selecting a dropdownlist item is done by setting the
SelectedItemIndex to an appropriate number.
"Simon Verona" <no****@nomail.zzz> wrote in message
news:%2****************@TK2MSFTNGP14.phx.gbl...
I posted this in dotnet.languages.vb.controls but thought I'd post here as
well..
I have a combobox that is bound to a dataview generated from a dataset.

The dataset has a single table (called "Data") with two columns "Id" and
"Description". Id contains a code and description contains the
description that is displayed in the combobox.

The dataview is generated from the dataset using dv =
ds.Tables("Data").DefaultView.

The Combobox is bound using :

txtLookup.DataSource = dv
txtLookup.ValueMember = "Id"

txtLookup.DisplayMember = "Description"

This works fine, I can read the current "Id" from the combobox using the
txtlookup.selectedvalue property.

However, if I want to programatically set the starting value of the
combobox, I can't seem to work out how to do it. I thought I could just
set the selectedvalue property to any of the vaules of "id" and the
combobox would then display the corresponding description. This appears
not to be the case. I don't know if it is getting confused by the fact
that the "Id" field in the datatable is numeric or if I'm just doing it
wrong!

What should I be doing?

Thanks in advance

Simon


Nov 21 '05 #3
Hi,

"Simon Verona" <no****@nomail.zzz> wrote in message
news:uG**************@TK2MSFTNGP15.phx.gbl...
But how do I know what the appropriate no is ???

If my datatable has for example:

Id Description
1 Ford
2 Vauxhall
3 Peugeot
6 Ferrari

and I want to set the combobox to "Ferrari" (ie ID=6).. How do I do this?

I'm trying to do : txtlookup.selectedvalue="6" but this isn't doing
what I expect!
You need to know the datatype of the "ValueMember" column and if it is by
example an integer and not a string then you would use:

txtlookup.SelectedValue = 6 ' without quotes
HTH,
Greetings


I presume that the selecteditemindex property is an offset through the
datatable. Do I have to scan through the datatable counting how far
through the record I want actually is? Will it matter that I've set the
combobox to sort by Description??

Regards
Simon
"Mr Newbie" <he**@now.com> wrote in message
news:OP*************@TK2MSFTNGP11.phx.gbl...
Combo box index are Zero based and incremental. Your ID column does not
have to correspond with this at all and can be any unique numbers. And
yes, selecting a dropdownlist item is done by setting the
SelectedItemIndex to an appropriate number.
"Simon Verona" <no****@nomail.zzz> wrote in message
news:%2****************@TK2MSFTNGP14.phx.gbl...
I posted this in dotnet.languages.vb.controls but thought I'd post here
as well..
I have a combobox that is bound to a dataview generated from a dataset.

The dataset has a single table (called "Data") with two columns "Id"
and "Description". Id contains a code and description contains the
description that is displayed in the combobox.

The dataview is generated from the dataset using dv =
ds.Tables("Data").DefaultView.

The Combobox is bound using :

txtLookup.DataSource = dv
txtLookup.ValueMember = "Id"

txtLookup.DisplayMember = "Description"

This works fine, I can read the current "Id" from the combobox using the
txtlookup.selectedvalue property.

However, if I want to programatically set the starting value of the
combobox, I can't seem to work out how to do it. I thought I could just
set the selectedvalue property to any of the vaules of "id" and the
combobox would then display the corresponding description. This appears
not to be the case. I don't know if it is getting confused by the fact
that the "Id" field in the datatable is numeric or if I'm just doing it
wrong!

What should I be doing?

Thanks in advance

Simon



Nov 21 '05 #4
I must be doing something very wrong because that doesn't help!

Even though the "Id" field contains numerics, it is defined as a string
field.

Regards
Simon
"Bart Mermuys" <bm*************@hotmail.com> wrote in message
news:eb**************@TK2MSFTNGP09.phx.gbl...
Hi,

"Simon Verona" <no****@nomail.zzz> wrote in message
news:uG**************@TK2MSFTNGP15.phx.gbl...
But how do I know what the appropriate no is ???

If my datatable has for example:

Id Description
1 Ford
2 Vauxhall
3 Peugeot
6 Ferrari

and I want to set the combobox to "Ferrari" (ie ID=6).. How do I do this?

I'm trying to do : txtlookup.selectedvalue="6" but this isn't doing
what I expect!


You need to know the datatype of the "ValueMember" column and if it is by
example an integer and not a string then you would use:

txtlookup.SelectedValue = 6 ' without quotes
HTH,
Greetings


I presume that the selecteditemindex property is an offset through the
datatable. Do I have to scan through the datatable counting how far
through the record I want actually is? Will it matter that I've set the
combobox to sort by Description??

Regards
Simon
"Mr Newbie" <he**@now.com> wrote in message
news:OP*************@TK2MSFTNGP11.phx.gbl...
Combo box index are Zero based and incremental. Your ID column does not
have to correspond with this at all and can be any unique numbers. And
yes, selecting a dropdownlist item is done by setting the
SelectedItemIndex to an appropriate number.
"Simon Verona" <no****@nomail.zzz> wrote in message
news:%2****************@TK2MSFTNGP14.phx.gbl...
I posted this in dotnet.languages.vb.controls but thought I'd post here
as well..
I have a combobox that is bound to a dataview generated from a dataset.

The dataset has a single table (called "Data") with two columns "Id"
and "Description". Id contains a code and description contains the
description that is displayed in the combobox.

The dataview is generated from the dataset using dv =
ds.Tables("Data").DefaultView.

The Combobox is bound using :

txtLookup.DataSource = dv
txtLookup.ValueMember = "Id"

txtLookup.DisplayMember = "Description"

This works fine, I can read the current "Id" from the combobox using
the txtlookup.selectedvalue property.

However, if I want to programatically set the starting value of the
combobox, I can't seem to work out how to do it. I thought I could
just set the selectedvalue property to any of the vaules of "id" and
the combobox would then display the corresponding description. This
appears not to be the case. I don't know if it is getting confused by
the fact that the "Id" field in the datatable is numeric or if I'm just
doing it wrong!

What should I be doing?

Thanks in advance

Simon



Nov 21 '05 #5
OK,

'For example, a delete operation

datasetMyVehicles.CarsTable.Rows.Find(
CarValueFromComboBoxInThisCaseItIs_6 ).Delete()

myDataAdapter.Update( datasetMyVehicles.CarsTable )
HTH
"Simon Verona" <no****@nomail.zzz> wrote in message
news:%2***************@TK2MSFTNGP15.phx.gbl...
I must be doing something very wrong because that doesn't help!

Even though the "Id" field contains numerics, it is defined as a string
field.

Regards
Simon
"Bart Mermuys" <bm*************@hotmail.com> wrote in message
news:eb**************@TK2MSFTNGP09.phx.gbl...
Hi,

"Simon Verona" <no****@nomail.zzz> wrote in message
news:uG**************@TK2MSFTNGP15.phx.gbl...
But how do I know what the appropriate no is ???

If my datatable has for example:

Id Description
1 Ford
2 Vauxhall
3 Peugeot
6 Ferrari

and I want to set the combobox to "Ferrari" (ie ID=6).. How do I do
this?

I'm trying to do : txtlookup.selectedvalue="6" but this isn't
doing what I expect!


You need to know the datatype of the "ValueMember" column and if it is by
example an integer and not a string then you would use:

txtlookup.SelectedValue = 6 ' without quotes
HTH,
Greetings


I presume that the selecteditemindex property is an offset through the
datatable. Do I have to scan through the datatable counting how far
through the record I want actually is? Will it matter that I've set
the combobox to sort by Description??

Regards
Simon
"Mr Newbie" <he**@now.com> wrote in message
news:OP*************@TK2MSFTNGP11.phx.gbl...
Combo box index are Zero based and incremental. Your ID column does not
have to correspond with this at all and can be any unique numbers. And
yes, selecting a dropdownlist item is done by setting the
SelectedItemIndex to an appropriate number.
"Simon Verona" <no****@nomail.zzz> wrote in message
news:%2****************@TK2MSFTNGP14.phx.gbl...
>I posted this in dotnet.languages.vb.controls but thought I'd post here
>as well..
>
>
> I have a combobox that is bound to a dataview generated from a
> dataset.
>
> The dataset has a single table (called "Data") with two columns "Id"
> and "Description". Id contains a code and description contains the
> description that is displayed in the combobox.
>
> The dataview is generated from the dataset using dv =
> ds.Tables("Data").DefaultView.
>
> The Combobox is bound using :
>
> txtLookup.DataSource = dv
> txtLookup.ValueMember = "Id"
>
> txtLookup.DisplayMember = "Description"
>
>
>
> This works fine, I can read the current "Id" from the combobox using
> the txtlookup.selectedvalue property.
>
> However, if I want to programatically set the starting value of the
> combobox, I can't seem to work out how to do it. I thought I could
> just set the selectedvalue property to any of the vaules of "id" and
> the combobox would then display the corresponding description. This
> appears not to be the case. I don't know if it is getting confused by
> the fact that the "Id" field in the datatable is numeric or if I'm
> just doing it wrong!
>
> What should I be doing?
>
>
>
> Thanks in advance
>
> Simon
>
>



Nov 21 '05 #6
Hi,

"Simon Verona" <no****@nomail.zzz> wrote in message
news:%2***************@TK2MSFTNGP15.phx.gbl...
I must be doing something very wrong because that doesn't help!

Even though the "Id" field contains numerics, it is defined as a string
field.
It would be strange that a numeric field would have a string datatype but it
shouldn't matter for the ComboBox, as long as you use the same type with
SelectedValue.

Check the column type (to be sure):
DataTable.Columns("id").DataType.ToString()

The ComboBox is visible and you are setting SelectedValue after the ComboBox
is bound, right ?
greetings

Regards
Simon
"Bart Mermuys" <bm*************@hotmail.com> wrote in message
news:eb**************@TK2MSFTNGP09.phx.gbl...
Hi,

"Simon Verona" <no****@nomail.zzz> wrote in message
news:uG**************@TK2MSFTNGP15.phx.gbl...
But how do I know what the appropriate no is ???

If my datatable has for example:

Id Description
1 Ford
2 Vauxhall
3 Peugeot
6 Ferrari

and I want to set the combobox to "Ferrari" (ie ID=6).. How do I do
this?

I'm trying to do : txtlookup.selectedvalue="6" but this isn't
doing what I expect!


You need to know the datatype of the "ValueMember" column and if it is by
example an integer and not a string then you would use:

txtlookup.SelectedValue = 6 ' without quotes
HTH,
Greetings


I presume that the selecteditemindex property is an offset through the
datatable. Do I have to scan through the datatable counting how far
through the record I want actually is? Will it matter that I've set
the combobox to sort by Description??

Regards
Simon
"Mr Newbie" <he**@now.com> wrote in message
news:OP*************@TK2MSFTNGP11.phx.gbl...
Combo box index are Zero based and incremental. Your ID column does not
have to correspond with this at all and can be any unique numbers. And
yes, selecting a dropdownlist item is done by setting the
SelectedItemIndex to an appropriate number.
"Simon Verona" <no****@nomail.zzz> wrote in message
news:%2****************@TK2MSFTNGP14.phx.gbl...
>I posted this in dotnet.languages.vb.controls but thought I'd post here
>as well..
>
>
> I have a combobox that is bound to a dataview generated from a
> dataset.
>
> The dataset has a single table (called "Data") with two columns "Id"
> and "Description". Id contains a code and description contains the
> description that is displayed in the combobox.
>
> The dataview is generated from the dataset using dv =
> ds.Tables("Data").DefaultView.
>
> The Combobox is bound using :
>
> txtLookup.DataSource = dv
> txtLookup.ValueMember = "Id"
>
> txtLookup.DisplayMember = "Description"
>
>
>
> This works fine, I can read the current "Id" from the combobox using
> the txtlookup.selectedvalue property.
>
> However, if I want to programatically set the starting value of the
> combobox, I can't seem to work out how to do it. I thought I could
> just set the selectedvalue property to any of the vaules of "id" and
> the combobox would then display the corresponding description. This
> appears not to be the case. I don't know if it is getting confused by
> the fact that the "Id" field in the datatable is numeric or if I'm
> just doing it wrong!
>
> What should I be doing?
>
>
>
> Thanks in advance
>
> Simon
>
>



Nov 21 '05 #7
Just to complete this thread, there was nothing actually wrong with the code
I had, the selectvalue works just fine. My problem was actually completely
unrelated to the combobox but was a corruption of the value that I was
setting the selectedvalue to!

Sometimes yuo just don't see the wood for the trees!!

Thanks

Regards
Simon
"Simon Verona" <no****@nomail.zzz> wrote in message
news:%2****************@TK2MSFTNGP14.phx.gbl...
I posted this in dotnet.languages.vb.controls but thought I'd post here as
well..
I have a combobox that is bound to a dataview generated from a dataset.

The dataset has a single table (called "Data") with two columns "Id" and
"Description". Id contains a code and description contains the
description that is displayed in the combobox.

The dataview is generated from the dataset using dv =
ds.Tables("Data").DefaultView.

The Combobox is bound using :

txtLookup.DataSource = dv
txtLookup.ValueMember = "Id"

txtLookup.DisplayMember = "Description"

This works fine, I can read the current "Id" from the combobox using the
txtlookup.selectedvalue property.

However, if I want to programatically set the starting value of the
combobox, I can't seem to work out how to do it. I thought I could just
set the selectedvalue property to any of the vaules of "id" and the
combobox would then display the corresponding description. This appears
not to be the case. I don't know if it is getting confused by the fact
that the "Id" field in the datatable is numeric or if I'm just doing it
wrong!

What should I be doing?

Thanks in advance

Simon

Nov 21 '05 #8

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

0
by: John Smith | last post by:
Hello all: Another day another problem :). How do you synch a databound combobox with the rest of the controls that are on a form. I have a combobox that lists a bunch of names and upon...
1
by: Prem S | last post by:
Hi All I have a databound ComboBox control which is put into the second page of a tab control. When the form loads up, I databind the combo control and populate the control. When I go to...
6
by: dbuchanan | last post by:
VS2005 I've been reading all the help I can on the topic (MSDN, other) but I can't make sense of this. Desired behavior; The user is to choose from the displayed list of the databound combobox...
3
by: Benny | last post by:
Does anyone know how I would go about adding a blank value to the list of items in a ComboBox that has a set datasource? Thank in advance!
3
by: greeknl via AccessMonster.com | last post by:
Is possible to save to a variable in VBA the value a combobox had before it was updated in order to use it because the update value can be retrieved easily Thank you -- Message posted via...
4
daffurankan
by: daffurankan | last post by:
Hai, this ankan here by this kindly tell me that how can i save a value in combobox which is type in its text field . on visual basic 6.0 act soon asap it is very important for me...
8
by: lttan123 | last post by:
hi there i am having some difficulties to bind value to combobox in windows application. combo.Items.Add(new List("a","b")) I have created a class. The value is there but what is displayed...
1
by: Joel1334 | last post by:
Hi! How can I change forecolor of a selected value in combobox? when I select a value in a combobox and press a button to "activate" what I've selected I want the text to be green and then...
0
by: wasim jack | last post by:
sir,I want to change value of combobox of datagridview on the basis of previous combobox value of the same raw of same datagridview
0
by: emmanuelkatto | last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud. Please let me know. Thanks! Emmanuel
1
by: nemocccc | last post by:
hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...
0
by: Hystou | last post by:
There are some requirements for setting up RAID: 1. The motherboard and BIOS support RAID configuration. 2. The motherboard has 2 or more available SATA protocol SSD/HDD slots (including MSATA, M.2...
0
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However,...
0
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can...
0
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new...
0
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.