[Solved] Null Reference Exception in Blend 4 if RadListPicker placed in Second Pivot Item

[Michael]

When using a PivotPage in Windows Phone 7 and insert a RadListPicker in the second PivotItem, i get a design error in Blend 4 with null reference exception.

Here is the Code. Any Ideas or is it a bug?

CAN COMPILE THIS CODE BUT GET AN ERROR:   

<Grid x:Name="LayoutRoot">
        <controls:Pivot Title="CATALOG" >
            <controls:PivotItem x:Name="PivotItemSearch" Header="Search"/>
            <controls:PivotItem x:Name="PivotItemGroups2" Header="Lines">
                <Grid Height="607" Width="456" d:LayoutOverrides="Width, Height" >
                    <telerikInput:RadListPicker x:Name="radListPicker" Margin="0,0,24,0" VerticalAlignment="Top"/>
                </Grid>
            </controls:PivotItem>
        </controls:Pivot>
    </Grid>

CAN COMPILE THIS CODE WITHOUT ERROR: 

<Grid x:Name="LayoutRoot">
        <controls:Pivot Title="CATALOG" >
            <controls:PivotItem x:Name="PivotItemSearch" Header="Search"/>
                 <Grid Height="607" Width="456" d:LayoutOverrides="Width, Height" >
                    <telerikInput:RadListPicker x:Name="radListPicker" Margin="0,0,24,0" VerticalAlignment="Top"/>
                </Grid>
            <controls:PivotItem x:Name="PivotItemGroups2" Header="Lines"/>
        </controls:Pivot>
    </Grid>

[Deyan]

Hi Michael,

Thanks for contacting us and for reporting this issue.

I would like to inform you that we have been able to reproduce the issue. It seems that when in a pivot item, the RadListPicker control does not resolve its template children in the OnApplyTemplate call. We have logged it in our issue tracking system and after we determine the reason for the erroreous behavior, we will provide a fix for it - hopefully for the upcoming internal build (due to next week).

I have updated your account with 1000 points for bringing this case to our attention.

Thanks for your time.

Best wishes,
Deyan
the Telerik team

[Flex]

Hi,

Is there already a fix for this problem?

[Deyan]

Hi Milan,

We are currently in the process of discussin the best possibilities to address this issue so that it does not affect the experience with our controls while using them in VS 2010 or Expression blend.

We hope that we will be able to provide a fix for Q2 2011 Beta2 or for the upcoming Q2 2011 release of RadControls for Windows Phone 7.

Do not hesitate to get back to us in case you have further questions or need assistance.

All the best,
Deyan
the Telerik team

[Arik]

I'm still seeing this behavior with the Q2 beta set of controls.  Is there an update?

Note:  Everything was fine on first configure -- it's after a rebuild/reopen that I'm seeing it.

[Deyan]

Hello Arik,

We are working on this issue and we hope that we will be able to provide a fix for it in Q2 2011 SP1. This seems to be a general issue with Expression Blend in which OnApplyTemplate for a given control is called but the GetTemplateChild method calls within it do not return any template children.

Feel free to write back anytime you have further questions or need assistance.

Regards,
Deyan
the Telerik team