GetPopupPlacement() null reference exception

[Scott]

I'm seeing a runtime error in the Telerik Silverlight controls (attached). I'm wondering if anyone has seen this error and has any advice on how to troubleshoot it.

[Rosen Vladimirov]

Hi Scott,

May I ask you for more details on your case - which of the Telerik Controls are you using and which one is raising this error? Are you using RadComboBox, RadMenu, RadDropDownButton, etc.?
In order to debug your Silverlight code you should enable Silverlight debugging in your ASP.NET project (if you have such) - right click on the ASP.NET project, go to Web and check the Silverlight Checkbox. After that go to Visual Studio's Debug menu, select Exceptions and check all of the boxes there. This way you'll be able to see exactly where the issue occurs.

I've recorded a short video demonstrating all of the above steps. Hope this helps.

Regards,
Rosen Vladimirov
Telerik

 

 

[Scott]

I'm using several controls such as RadBusyIndicator, RadDocking, RadDatePicker, RadNumericUpDown, etc. The one that is causing the error is RadComboBox. Enabling Silverlight Debugging caused some different behavior but didn't give me much more information. Instead of the original error I got a prompt to debug in a new instance of Visual Studio (attached JIT.png). When I tried that, I just got a similar error (attached unhandledexception.png). There was a little more detail in the stack trace (attached stacktrace.PNG).

[Rosen Vladimirov]

Hi Scott,

May I ask you for more details on your scenario - we've tried to reproduce the issue based on the stack trace, but with no luck. Could you provide some parts of your code, so we'll be able to investigate the issue on our side. It looks like the problem is caused by the Popup of RadComboBox, you can try turning AnimationManager off for RadComboBox (set telerik:AnimationManager.IsAnimationEnabled="False").

I'm looking forward to hearing from you.

Regards,
Rosen Vladimirov
Telerik

 

 

[Scott]

We are using it in a DataTemplate such as (with all variables renamed to foo):

<DataTemplate x:Key="DropdownTemplate">

    <telerik:RadComboBox ItemsSource="{Binding foo}"
                         Text="{Binding foo, Mode=OneWay}"

                  Background="{Binding foo}" Foreground="{Binding foo}"

                  OpenDropDownOnFocus="{Binding foo}"

                  IsEnabled="{Binding Path=foo, Converter={StaticResource foo}}"

                  IsEditable="{Binding Path=foo, Converter={StaticResource foo}}"

                  KeyUp="RadComboBox_KeyUp"

                  LostFocus="RadComboBox_LostFocus"

                  SelectionChanged="RadComboBox_SelectionChanged"/>

</DataTemplate>

Is there a way to set that declaratively in the xaml?

[Kalin]

Hi Scott,

Thank you for sharing these details. You can set the IsAnimationEnabled property in XAML:

<telerik:RadComboBox ItemsSource="{Binding foo}" telerik:AnimationManager.IsAnimationEnabled="False" >

Could you share some more details on your case, what is this DataTemplate - are you using RadComboBox inside RadDropDownButton? If you can provide sample application reproducing the issue, it will be a great help for us.

I'm looking forward to hearing from you.

Regards,
Kalin
Telerik

 

 

[Scott]

Unfortunately setting IsAnimationEnabled to false did not fix the issue. I can confirm that the issue doesn't happen in IE 11, Chrome, or Firefox. It only happens in IE 10.

Regarding the DataTemplate: it is not inside a RadDropDownButton. I inherited this code so I'm not completely familiar with it. It is used by a Telerik.Windows.Controls.DataTemplateSelector. I'm not sure how to get you a sample to reproduce it.

Thanks,
Scott

[Kalin]

Hi Scott,

Could you please share the code of the DataTemplateSelector you have implemented as well as the Xaml where you are using it? On which control you are applying it?

I'm looking forward to your reply.

Regards,
Kalin
Telerik

 

 

[Scott]

This is not the exact code but hopefully it shows you enough context of what we are doing.

Xaml:

<DataTemplate x:Key="DropdownTemplate">
  <telerik:RadComboBox ItemsSource="{Binding foo}"
     Text="{Binding foo, Mode=OneWay}"
     Background="{Binding foo}" Foreground="{Binding foo}"
     OpenDropDownOnFocus="{Binding foo}"
     IsEnabled="{Binding Path=foo, Converter={StaticResource foo}}"
     IsEditable="{Binding Path=foo, Converter={StaticResource foo}}"
     KeyUp="RadComboBox_KeyUp"
     LostFocus="RadComboBox_LostFocus"
     SelectionChanged="RadComboBox_SelectionChanged"/>
</DataTemplate>

<local:PropertyValueCellTemplateSelector x:Key="valueCellTemplateSelector"
  FooTemplate="{StaticResource FooTemplate}"
  ValueChoiceTemplate="{StaticResource DropdownTemplate}"/>

<telerik:RadGridView Name="fooGridView"
  ItemsSource="{Binding foo}"
  AutoGenerateColumns="False"
  CanUserResizeColumns="True"
  CanUserSortColumns="False"
  CanUserInsertRows="False"
  CanUserReorderColumns="False"
  IsFilteringAllowed="False"
  ShowColumnHeaders="False"
  AutoExpandGroups="True"
  ShowGroupPanel="False"
  RowIndicatorVisibility="Collapsed"
  RowLoaded="propertiesGridView_RowLoaded"
  SelectedItem="{Binding foo, Mode=TwoWay}"
  SelectionMode="Single"
  VerticalContentAlignment="Top"
  HorizontalContentAlignment="Left"
  ScrollMode="Deferred"
  CanUserDeleteRows="False" >
  <telerik:GridViewDataColumn Header="foo"
    DataMemberBinding="{Binding foo, Mode=TwoWay}"
    CellTemplateSelector="{StaticResource valueCellTemplateSelector}"
    EditTriggers="TextInput" IsReadOnly="True"/>
</telerik:RadGridView>

VB.NET:

Imports Telerik.Windows.Controls

Public Class PropertyValueCellTemplateSelector
    Inherits DataTemplateSelector

    Public Sub New()
    End Sub

    Public Property FooTemplate() As DataTemplate
    Public Property ValueChoiceTemplate As DataTemplate

    Public Overloads Overrides Function SelectTemplate(ByVal item As Object, ByVal container As DependencyObject) As DataTemplate
        Dim foo As Bar = CType(item, Bar)
        MyBase.SelectTemplate(item, container)
        If foo.Bar IsNot Nothing Then
            Return Me.ValueChoiceTemplate
        Else
            Return Me.FooTemplate
        End If

End Class

[Kalin]

Hi Scott,

I was not able to reproduce the described issue in sample project using the provided code snippets. I'm attaching the test project here and if you are able to modify it in order to reproduce the issue that would be really helpful for us.

I'm looking forward to hearing from you.

Regards,
Kalin
Telerik