Custom Control ITemplate Property Error

[Eric]

I have created a custom control which includes a RadScheduler as one of its child controls. I exposed the AdvancedEditTemplate and AdvancedInsertTemplate properties of the RadScheduler in my custom control as shown in the example below.

	Imports Telerik.Web.UI
	Public NotInheritable Class CustomScheduler
	Inherits CompositeControl
	Private WithEvents mScheduler As RadScheduler
	<TemplateContainer(GetType(BTAppointmentScheduler)), _
	PersistenceMode(PersistenceMode.InnerProperty)> _
	Public Property AppointmentFormTemplate() As ITemplate
	Get
	EnsureChildControls()
	Return mScheduler.AdvancedEditTemplate
	End Get
	Set(ByVal value As ITemplate)
	EnsureChildControls()
	mScheduler.AdvancedEditTemplate = value
	mScheduler.AdvancedInsertTemplate = value
	End Set
	End Property
	Protected Overrides Sub CreateChildControls()
	Controls.Clear()
	mScheduler = New RadScheduler()
	Controls.Add(mScheduler)
	End Sub
	Protected Overrides Sub Render(ByVal writer As HtmlTextWriter)
	mScheduler.RenderControl(writer)
	End Sub
	End Class

Then I setup my aspx page similiar to the example below.

	<my:CustomScheduler ID="CustomScheduler1" runat="server">
	<AppointmentFormTemplate>
	<asp:TextBox ID="SubjectTextBox" runat="server" Rows="5" Columns="20" Text='<%# Bind("Subject") %>' Width="95%" TextMode="MultiLine"></asp:TextBox>
	...
	</AppointmentFormTemplate>
	</my:CustomScheduler>

Whenever, I try to create an appointment I get the following exception:

Unable to cast object of type 'System.Web.UI.CompiledTemplateBuilder' to type 'System.Web.UI.IBindableTemplate'.

atTelerik.Web.UI.RadScheduler.CreateFormContainer()
atTelerik.Web.UI.RadScheduler.CreateChildControls(BooleanbindFromDataSource)
atTelerik.Web.UI.RadScheduler.CreateChildControls()
atSystem.Web.UI.Control.EnsureChildControls()
atSystem.Web.UI.Control.PreRenderRecursiveInternal()
atSystem.Web.UI.Control.PreRenderRecursiveInternal()
atSystem.Web.UI.Control.PreRenderRecursiveInternal()
atSystem.Web.UI.Control.PreRenderRecursiveInternal()
atSystem.Web.UI.Control.PreRenderRecursiveInternal()
atSystem.Web.UI.Control.PreRenderRecursiveInternal()
atSystem.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint,Boolean includeStagesAfterAsyncPoint)

What am I doing wrong?

[Atanas Korchev]

Hi Eric,

Please try applyting this attribute:

<TemplateContainer(GetType(BTAppointmentScheduler), BindingDirection.TwoWay)>
Best wishes,
Albert
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[Eric]

That seems to have resolved the cast exception in RadScheduler.CreateFormContainer(). I am now getting the following cast exception during databinding.

Unable to cast object of type 'Telerik.Web.UI.SchedulerFormContainer' to type 'MyProject.CustomScheduler'.

at ASP.default_aspx.__DataBinding__control7(Object sender, EventArgs e) in C:\projects\MyProject\Default.aspx:line 36

at System.Web.UI.Control.OnDataBinding(EventArgs e)

at System.Web.UI.WebControls.CompositeControl.DataBind()

at System.Web.UI.Control.DataBindChildren()

at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)

at System.Web.UI.Control.DataBind()

at Telerik.Web.UI.RadScheduler.CreateChildControls(Boolean bindFromDataSource)

at Telerik.Web.UI.RadScheduler.CreateChildControls()

at System.Web.UI.Control.EnsureChildControls()

at System.Web.UI.Control.PreRenderRecursiveInternal()

at System.Web.UI.Control.PreRenderRecursiveInternal()

at System.Web.UI.Control.PreRenderRecursiveInternal()

at System.Web.UI.Control.PreRenderRecursiveInternal()

at System.Web.UI.Control.PreRenderRecursiveInternal()

at System.Web.UI.Control.PreRenderRecursiveInternal()

at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

[Eric]

I must have made a build error. It is working correctly now. Thanks.

[Eric]

It was not a build issue that caused the cast exception during databinding. I had temporarily removed the binding expression. When I added it back in the exception returned.

[Eric]

I was able to resolve the cast exception on data binding by changing the TemplateContainerAttribute as follows:

<TemplateContainer(GetType(SchedulerFormContainer), BindingDirection.TwoWay)>