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I am going crazy trying to figure out how to manipulate telerik RadGridView for WPF's column filtering from my ViewModel. I thought I might be able to bind the value of a FilterDescriptor to a ViewModel property, but I get

Cannot find governing FrameworkElement or FrameworkContentElement for target element

<telerik:CompositeFilterDescriptor>
                    <telerik:FilterDescriptor Member="Foo.SomeProperty" Operator="IsContainedIn" Value="{Binding SelectedThings}" />
                </telerik:CompositeFilterDescriptor>

where Foo.SomeProperty is a VM property bound to a grid column and SelectedThings is a VM property containing a stringified array of unique values to filter against.

GridView is bound to a QueryableCollectionView.

I want the filtering to work at runtime, based upon some custom logic in the VM - ex. user clicks some button and the VM restricts distinct values of one of the columns.

This shouldn't be so hard. I must be approaching this wrong. I've been pooring over other stackoverflow questions but haven't found a solution that works yet. Any suggestions would be appreciated.

UPDATE

I would still like to achieve this with a completely MVVM approach, but for the time being I've decided to stop going nuts over it and resolve the issue in the following way.

ViewModel's ObservableCollection which is bound to a list of checkboxes representing some filtering criteria are updated by the user through the GUI.

Upon that property change the ViewModel sends a message via Messenger (MVVMLIGHT) which in the codebehind has registered to receive. The message includes the filtering criteria information.

The codebehind receives it and applies it directly to the GridView.

What's nice about this is it avoids having to wire up any DependencyProperties or other event handlers and allows the VM to remain ignorant of the View implementation. It's simple and it works.

Yes, there's a little code behind now, but until I can find some better info on how to solve this problem purely through MVVM binding, this is a workable solution.

Wish I'd done this at 9 AM yesterday instead of banging my head against the wall all day long reading Telerik's crappy documentation and hunting for examples of how to do it "the right way". Meh.

jayint32
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    I guess the binding doesn't work because "FilterDescriptor" isn't part of the visual tree ... maybe use a data context proxy? See: http://stackoverflow.com/questions/7660967/wpf-error-cannot-find-govering-frameworkelement-for-target-element – McGarnagle May 23 '14 at 15:08
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    You're back on the case, McGarnagle! Thanks very much. That works great even it it is a wee bit hacky. Better than fudging up my code behind with GUI manipulating code. – jayint32 May 27 '14 at 15:26

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