[Solved] GridViewScrollViewerTemplate NullReference error when editing the template on expression blend

[Ivan]

Hi I cannot edit on expression blend the GridViewScrollViewer template

I get a null reference error

<!--Begin GridViewScrollViewer-->
<ControlTemplate x:Key="GridViewScrollViewerTemplate"
                 TargetType="telerik:GridViewScrollViewer">
    <Grid x:Name="PART_RootPanel"
          Background="{TemplateBinding Background}">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="Auto" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <telerik:ScrollContentPresenter Grid.Row="2"
                                        CanContentScroll="{TemplateBinding CanContentScroll}" />
        <ScrollBar x:Name="PART_VerticalScrollBar"
                   IsTabStop="False"
                   Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}"
                   Grid.Column="1"
                   Grid.Row="0"
                   Grid.RowSpan="4"
                   Orientation="Vertical"
                   ViewportSize="{TemplateBinding ViewportHeight}"
                   Maximum="{TemplateBinding ScrollableHeight}"
                   Minimum="0.0"
                   Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}"
                   telerik:StyleManager.Theme="{StaticResource Theme}" />

        <ScrollBar x:Name="PART_HorizontalScrollBar"
                   IsTabStop="False"
                   Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}"
                   Grid.Column="0"
                   Grid.Row="4"
                   Orientation="Horizontal"
                   ViewportSize="{TemplateBinding ViewportWidth}"
                   Maximum="{TemplateBinding ScrollableWidth}"
                   Minimum="0.0"
                   Value="{Binding HorizontalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}"
                   telerik:StyleManager.Theme="{StaticResource Theme}" />
        <Rectangle Grid.Column="1"
                   Grid.Row="4"
                   Fill="{StaticResource MainBrush}" />
    </Grid>
</ControlTemplate>
<Style TargetType="telerik:GridViewScrollViewer">
    <Setter Property="Template"
            Value="{StaticResource GridViewScrollViewerTemplate}" />
</Style>
<!--End GridViewScrollViewer-->

[Vanya Pavlova]

Hello Ivan,

 
Indeed we are aware of such an issue related to the Blend Support of RadGridView.


For the time being I may suggest you to use the following workaround:
Before dropping the GrdViewScrollViewer just get an empty RadGridView from Assets library and drop it onto the Artboard. Then you will not get this exception within Expession Blend's design surface. 


Please excuse us for any inconvenience caused!

Regards,
Vanya Pavlova
the Telerik team

[Ivan]

Thanks for your answer Vanya,

I will try it...

Just one more thing I'm getting the NullReference error on runtime but it doesn't appear very frequently (in a RadGridView with too many columns with the HorizontalScrollbar visible), it happens once time a day I think and it is when i move the HorizontalScrollBar... my application crashes after the error...

BTW are you russian?

Best Regards...

[Vanya Pavlova]

Hello Ivan,

 

May you post more info about the grid version? Is it our latest official release Q2 2011?

Greetings,
Vanya Pavlova
the Telerik team

[Ivan]

Hi Vanya


I'm using the next version     RadControls_for_Silverlight4_2011_2_0815


Also is very difficult to replicate the error, like I told you doesn't happen very often


Best Regards,
Ivan

[Vanya Pavlova]

Hello Ivan,

 


Regarding the fact that this behavior does not  always happen it is hard to determine what might be causing it. For the time being I hope that the proposed workaround in my previous reply is enough to avoid this error. 

Best wishes,
Vanya Pavlova
the Telerik team