WPFToolKit Feb, AccordionItem not usable in Blend3/4 ?

Aug 19, 2010 at 7:27 PM


I am trying to use Blend3/4 to make visual changes to one of my project that make use of Accordion that is included in the Feb release(this is .NET 3.5 target).

However, both would come out with 'object reference not set to an instance of an object' error when it tried to load the AccordionItem control.

I have isolated that to be something about the mix between Blend and AccordionItem as a blank WPFApplication created where I just drag an Accordion then AccordionItem into it would result in the exact same issue.

Does anyone know how I can style AccordionItem in Blend 3/4 ?

Aug 20, 2010 at 2:07 AM

Looks like a bug in the AccordionItem some where that expects thing in a sequence that is not present when being loaded in Blend.

The only work around I can find is to click on those 'null pointer exceptions' one by one and make trivial change to the XAML(any random thing to invalidate the XAML then change it back) and some how the error would go away.

This means I need to have both VS 2008 and Blend(3 in this case) opened and never close Blend. Just save the changes, let VS 2008 pickup and recompile ...

Frustrating and seems to be a bug being there for quite a while.