2nd Post: Problem adding events to controls created at run-time

**Bart Mermuys** · Feb 6 '06, 11:35 PM

Re: 2nd Post: Problem adding events to controls created at run-time

Hi,

"Steve Moreno" <SteveMoreno@di scussions.micro soft.com> wrote in message
news:A98C5DF6-484A-4B4A-9671-04B5DE6D7D86@mi crosoft.com...[color=blue]
> Hi all,
>
> I've got a web form that I've written code to create an array of
> DropDownList controls on the page depending on how many records are pulled
> back. The code to create the controls is working fine but now I need to
> add
> events to the newly created DropDownList controls. I need to add the
> SelectedIndexCh anged event and I'm having a hard time getting the code to
> add
> events to the controls since the names (IDs) are varied to include the
> record
> row number like "name & (int)".
>
> I've seen examples on other web-sites which have either syntax errors
> and/or
> so do not compile on my pc. So my question is this...
>
> If I have a group of dropdownlistbox es named dlstDropDown and I have
> changed
> the ID of the controls before I add the control to my page to include an
> index so they would be dlstDropDown0, dlstDropDown1, dlstDropDown2, etc...
> How do I add a SelectedIndexCh anged event to each of them? And/Or how
> would
> I go about creating a generic private sub to capture this event?
>
> What I've tried so far with no success is:
>
> 'before I add the control to the page
> AddHandler dlstWindow.Sele ctedIndexChange d, AddressOf _
> Me.dlstWindow_S electedIndexCha nged
>
> It looks like the event either doesn't fire or isn't in the correct[/color]

I rarely make webapplications , but from what i remember you need to
re-create the dynamic Controls in Page_Load with the same ID. WebPage's are
static, so when the page is loaded again (because of postback) the dynamic
controls are gone so their events can't fire. But if you re-create them
inside Page_Load with the same id, then their events will fire.

HTH,
Greetings

[color=blue]
> AddressOf. This is the sub I've been playing with:
>
> Private Sub dlstWindow_Sele ctedIndexChange d(ByVal sender As Object, ByVal
> _
> e As System.EventArg s)
>
> Dim strCurrentID As String
> Dim currentDropDown List As DropDownList = CType(sender,
> DropDownList)
>
> strCurrentID = currentDropDown List.ID
>
> End Sub
>
> I'm using 2003 (haven't migrated to 2005 yet). Any help would be greatly
> appreciated. I've already burned an entire week on this and am working on
> burning another one. :(
>
> thanks in advance,
> Steve.
>[/color]

**Cor Ligthert [MVP]** · Feb 7 '06, 06:55 AM

Re: 2nd Post: Problem adding events to controls created at run-time

[color=blue]
> I rarely make webapplications , but from what i remember you need to
> re-create the dynamic Controls in Page_Load with the same ID. WebPage's
> are static, so when the page is loaded again (because of postback) the
> dynamic controls are gone so their events can't fire. But if you
> re-create them inside Page_Load with the same id, then their events will
> fire.
>[/color]
exact

:-)

Cor

**Steve Moreno** · Feb 7 '06, 02:15 PM

Re: 2nd Post: Problem adding events to controls created at run-tim

Thanks for trying to help. I am already generating these controls on the
Page_Load event. I'm thinking the SelectedIndexCh anged events are firing but
maybe my syntax for the handler sub is incorrect? Please check below and see
if you can find an issue why this doesn't work.

Thanks In Advance Again.
Steve.

"Bart Mermuys" wrote:
[color=blue]
> Hi,
>
> "Steve Moreno" <SteveMoreno@di scussions.micro soft.com> wrote in message
> news:A98C5DF6-484A-4B4A-9671-04B5DE6D7D86@mi crosoft.com...[color=green]
> > Hi all,
> >
> > I've got a web form that I've written code to create an array of
> > DropDownList controls on the page depending on how many records are pulled
> > back. The code to create the controls is working fine but now I need to
> > add
> > events to the newly created DropDownList controls. I need to add the
> > SelectedIndexCh anged event and I'm having a hard time getting the code to
> > add
> > events to the controls since the names (IDs) are varied to include the
> > record
> > row number like "name & (int)".
> >
> > I've seen examples on other web-sites which have either syntax errors
> > and/or
> > so do not compile on my pc. So my question is this...
> >
> > If I have a group of dropdownlistbox es named dlstDropDown and I have
> > changed
> > the ID of the controls before I add the control to my page to include an
> > index so they would be dlstDropDown0, dlstDropDown1, dlstDropDown2, etc...
> > How do I add a SelectedIndexCh anged event to each of them? And/Or how
> > would
> > I go about creating a generic private sub to capture this event?
> >
> > What I've tried so far with no success is:
> >
> > 'before I add the control to the page
> > AddHandler dlstWindow.Sele ctedIndexChange d, AddressOf _
> > Me.dlstWindow_S electedIndexCha nged
> >
> > It looks like the event either doesn't fire or isn't in the correct[/color]
>
> I rarely make webapplications , but from what i remember you need to
> re-create the dynamic Controls in Page_Load with the same ID. WebPage's are
> static, so when the page is loaded again (because of postback) the dynamic
> controls are gone so their events can't fire. But if you re-create them
> inside Page_Load with the same id, then their events will fire.
>
> HTH,
> Greetings
>
>[color=green]
> > AddressOf. This is the sub I've been playing with:
> >
> > Private Sub dlstWindow_Sele ctedIndexChange d(ByVal sender As Object, ByVal
> > _
> > e As System.EventArg s)
> >
> > Dim strCurrentID As String
> > Dim currentDropDown List As DropDownList = CType(sender,
> > DropDownList)
> >
> > strCurrentID = currentDropDown List.ID
> >
> > End Sub
> >
> > I'm using 2003 (haven't migrated to 2005 yet). Any help would be greatly
> > appreciated. I've already burned an entire week on this and am working on
> > burning another one. :(
> >
> > thanks in advance,
> > Steve.
> >[/color]
>
>
>[/color]

**Steve Moreno** · Feb 7 '06, 02:45 PM

RE: 2nd Post: Problem adding events to controls created at run-time

Got it!!!!!!!!!!!!! !

With the replies I've received from Ken, Bart, and Cor I've realized that I
had the code that creates the controls within a "If Not IsPostBack Then"
block and so the controls were not being re-created and thus events were
indeed not firing. Something so obvious and yet not obvious until you hear
from others... Now that I've modified the code to reside outside of the "If
Not IsPostBack Then" block, it works GREAT!

Thanks to all who have replied.
Steve.

"Steve Moreno" wrote:
[color=blue]
> Hi all,
>
> I've got a web form that I've written code to create an array of
> DropDownList controls on the page depending on how many records are pulled
> back. The code to create the controls is working fine but now I need to add
> events to the newly created DropDownList controls. I need to add the
> SelectedIndexCh anged event and I'm having a hard time getting the code to add
> events to the controls since the names (IDs) are varied to include the record
> row number like "name & (int)".
>
> I've seen examples on other web-sites which have either syntax errors and/or
> so do not compile on my pc. So my question is this...
>
> If I have a group of dropdownlistbox es named dlstDropDown and I have changed
> the ID of the controls before I add the control to my page to include an
> index so they would be dlstDropDown0, dlstDropDown1, dlstDropDown2, etc...
> How do I add a SelectedIndexCh anged event to each of them? And/Or how would
> I go about creating a generic private sub to capture this event?
>
> What I've tried so far with no success is:
>
> 'before I add the control to the page
> AddHandler dlstWindow.Sele ctedIndexChange d, AddressOf _
> Me.dlstWindow_S electedIndexCha nged
>
> It looks like the event either doesn't fire or isn't in the correct
> AddressOf. This is the sub I've been playing with:
>
> Private Sub dlstWindow_Sele ctedIndexChange d(ByVal sender As Object, ByVal _
> e As System.EventArg s)
>
> Dim strCurrentID As String
> Dim currentDropDown List As DropDownList = CType(sender, DropDownList)
>
> strCurrentID = currentDropDown List.ID
>
> End Sub
>
> I'm using 2003 (haven't migrated to 2005 yet). Any help would be greatly
> appreciated. I've already burned an entire week on this and am working on
> burning another one. :(
>
> thanks in advance,
> Steve.
>[/color]

**smg1965** · Feb 10 '06, 04:36 PM

Had same problem, hence the reason for finding this thread.

Solved by adding this last line to similar code:

quest_id = New DropDownList
AddHandler quest_id.Select edIndexChanged, AddressOf updateScore
quest_id.AutoPo stBack = True

The event now fires!

2nd Post: Problem adding events to controls created at run-time

2nd Post: Problem adding events to controls created at run-time

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