System.ArgumentException When Implementing GroupDescriptor

[Glenn]

I'm still very new to Telerik and still getting to know all the ins and outs of the controls.  What I'm doing is implementing a simple grouping mechanism to simulate a property grid.

XAML:

<telerik1:RadGridView Name="ParametersGridView"

                      CanUserDeleteRows="False"

                      CanUserInsertRows="False"

                      IsReadOnly="False"

                      AutoExpandGroups="True"

                      ShowGroupPanel="False"

                      ShowColumnHeaders="False"

                      AutoGenerateColumns="False"

                      HorizontalContentAlignment="Stretch"

                      HorizontalAlignment="Stretch"

                      VerticalContentAlignment="Stretch"

                      VerticalAlignment="Stretch"

                      RowLoaded="ParametersGridView_RowLoaded">

      

    <telerik1:RadGridView.GroupDescriptors>

        <telerikData:GroupDescriptor Member="Category"

                                     SortDirection="Ascending" />

    </telerik1:RadGridView.GroupDescriptors>

      

    <telerik1:RadGridView.Resources>

        <DataTemplate x:Key="GridToolTip">

            <StackPanel Orientation="Horizontal">

                <TextBlock Text="{Binding Description}" 

                           MaxWidth="300"

                           TextWrapping="Wrap" />

            </StackPanel>

        </DataTemplate>

    </telerik1:RadGridView.Resources>



    <telerik1:RadGridView.Columns>

        <telerik1:GridViewDataColumn Header="Parameter"

                                     DataMemberBinding="{Binding DisplayName}"

                                     Width="150"

                                     IsReadOnly="True" />

        <my:ConfigDataColumn Header="Value"

                              DataMemberBinding="{Binding Value,Mode=TwoWay}"

                              Width="300"

                              IsReadOnly="False" />

        <telerik1:GridViewDataColumn Header="Category"

                                     DataMemberBinding="{Binding Category}"

                                     IsReadOnly="True"

                                     IsVisible="False" />

    </telerik1:RadGridView.Columns>

</telerik1:RadGridView>

I load up the RadGridView.ItemsSource in the control's Loaded event.  When I run it, everything works just fine as expected.  However, when I try to view my control in the VS designer, I get a System.ArgumentException stating:"Invalid property or field - 'Category' for type: Customer".

First of all, I don't know where the "Customer" is coming from, there's no such class/object in my code.  Secondly, is this exception normal since I load my data at runtime?

...Glenn

[Vlad]

Hi Glenn,

 Do you have our latest version - Q2 2010? We had previously such problems due to our design-time data source (Customers) however this is now removed completely. 

Best wishes,
Vlad
the Telerik team

[Glenn]

Looks like we're still running Q3 2009.  We'll get the latest and re-test.