"Jim Butler" <bigbarley@noemail.noemail> wrote in message
news:u08RvhjaGHA.4772@TK2MSFTNGP05.phx.gbl...
> We have a set of web server controls that inherit directly from their
> parent web server control and implement INamingContainer. We need our
> code to be 508 compliant but are having trouble with the FindControl
> method in AddAttributesToRender does not find the AssociatedControlID.
> Our test label class is completely devoid of custom [rendering] code. We
> use the INamingContainer within our web server controls for unique id
> generation for those controls when nested within user controls and so
> fourth. Problem when the code is rendered, an Exception is generated like
> the one below.
>
> System.Web.HttpException: Unable to find control with id 'hospital_id2'
> that is associated with the Label 'lbl_hospital_id2'.
> at System.Web.UI.WebControls.Label.AddAttributesToRender(HtmlTextWriter
> writer)
> at System.Web.UI.WebControls.WebControl.RenderBeginTag(HtmlTextWriter
> writer)
> at System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
> at .... for brevity
>
> From this aspx code
> <form runat="Server">
> <bl:TestLabel id="lbl_hospital_id2" Text="Hello World22"
> AssociatedControlID="hospital_id2" runat="server" />
> <bl:TestLabel id="hospital_id2" Text="Hello World2222" runat="server"
> />
> </form>
>
> Public Class TestLabel
> Inherits System.Web.UI.WebControls.Label
> Implements System.Web.UI.INamingContainer
>
> Private Sub TestLabel_PreRender(ByVal sender As Object, ByVal e As
> System.EventArgs) Handles Me.PreRender
> Dim x As String = ""
> End Sub
> End Class
>
>
> Thanks in advance,
>
> Jim Butler
>

"Steven Cheng[MSFT]" <stcheng@online.microsoft.com> wrote in message
news:oULhwloaGHA.880@TK2MSFTNGXA01.phx.gbl...
> Hi Jim,
>
> Welcome to the ASP.NET newsgroup.
>
> From your description, I understand you're developing a custom label
> control which will use the Render out some custom attributes, and you're
> using the "AddAttributesToRender" method to add some certain attributes
> into the control tag, and one of them is a string value reference to other
> control on the page. However, when you try using the FindControl method to
> locate other control on the page, you're getting error, correct?
>
> Based on my understanding, the FindControl method will only search the
> control (by id) in the current NamingContainer.
>
> #Control.FindControl Method (String)
> http://msdn2.microsoft.com/en-us/library/486wc64h.aspx
>
> And as for your scenario, your custom control has implemented the
> INamingContainer interface, then, the FindControl method of itself will
> only be able to find control in its own child control collection. And for
> other controls at the same level (in the same parent NamingContainer), it
> will not be able to find them. We have to call the FindControl on the
> parent NamingContainer, like:
>
> ===============================
> protected override void AddAttributesToRender(HtmlTextWriter writer)
> {
>
> writer.AddAttribute(HtmlTextWriterAttribute.Id, ID);
>
>
> if (!string.IsNullOrEmpty(AssociatedControlID))
> {
> Control ctrl =
> this.NamingContainer.FindControl(AssociatedControlID);
>
> writer.AddAttribute(HtmlTextWriterAttribute.For,
> ctrl.ClientID);
> }
>
> }
> ============================
>
> Hope this helps.
>
> Regards,
>
> Steven Cheng
> Microsoft Online Community Support
>
>
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"Steven Cheng[MSFT]" <stcheng@online.microsoft.com> wrote in message
news:NRUQIfQbGHA.1764@TK2MSFTNGXA01.phx.gbl...
> Thanks for your response Jim,
>
> As for the INamingContainer, and FindControl method, it is the fixed by
> design behavior that the control searching will only be performed within
> the current NamingContainer scope.
>
> As for the further concerns you mentioned:
> =======================
> After decompiling the built in method, we are
> concerned we might be losing added functionality, such as AccesKey,
> disabled, tabIndex and so on. The problem with trying to use the one's
> listed is that in the inherited class we don't seem to have access to all
> the variables to duplicate the code.
> ======================
>
> Do you means the reuse of those existing properties such as AccessKey,
> TableIndex, Font ... on the WebControl class? Generally for those common
> properties or reusable ones, the classes will mark them as "public
> virtual"
> so that our dervied class can override them. And yes, some variables or
> properties, methods are marked as internal, that means the library
> designer
> do not want it open to other developers. In such scenario, we could not
> but
> implement our own according to the code logic or we can create a own code
> library to reuse them just like the framework fundamental library.
>
> Regards,
>
> Steven Cheng
> Microsoft Online Community Support
>
>
> ==================================================
>
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
>
> ==================================================
>
>
> This posting is provided "AS IS" with no warranties, and confers no
> rights.
>
>
>
> Get Secure! www.microsoft.com/security
> (This posting is provided "AS IS", with no warranties, and confers no
> rights.)
>