AssociatedObject object is always null for gridViewColumn

[ken]

Hi there, I am trying to create a behavior I can use to set the width of certain columns to 0 if certain things happen but when I try to access the AssociatedObject it is always null. I think the code will better explain this...

public static readonly DependencyProperty VisibilityProperty =
        DependencyProperty.Register("Visibility", typeof(bool), typeof(HideRadGridViewColumnBehavior),
        new PropertyMetadata(OnVisibilityPropertyChanged));

private static void OnVisibilityPropertyChanged(DependencyObject target, DependencyPropertyChangedEventArgs args)
{
  if (((HideRadGridViewColumnBehavior)target).AssociatedObject == null)
  {
    MessageBox.Show("AssociatedObject is null");
  }
  else
  {
    var col = ((HideRadGridViewColumnBehavior)target).AssociatedObject as GridViewDataColumn;
    col.Width = 0;
    col.Header = "";
    col.IsResizable = false;
  }
}

It's fairly obvious what I want to do there however no matter what the AssociatedObject is null, Here is the XAML I am using - hopefully someone can point me in the right direction on this.

<telerik:GridViewDataColumn DataMemberBinding="{Binding ModelId}"  Header="ID">
  <i:Interaction.Behaviors>
    <b:HideRadGridViewColumnBehavior Visibility="{Binding Path=DevMode}"/>
  </i:Interaction.Behaviors>
</telerik:GridViewDataColumn>

Thanks alot!!!

[Ivan Ivanov]

Hi ken,

I tried compiling a sample project, using your code snippets, but I couldn't actually make it really work. Could you please have a look at it and inform me if there are any differences between your approach and mine.

Best wishes,
Ivan Ivanov
the Telerik team

[Ivan Ivanov]

Hello ken,

Please excuse me, I have sent you a wrong project in my previous post.

All the best,
Ivan Ivanov
the Telerik team

[ken]

Opps - I don't have the Silverlight SDK. This is for a WPF desktop app.

[Ivan Ivanov]

Hi ken,

RadGridView's columns are not visual objects, so they are not added to the visual tree. Please check this example: Examples > RadGridView > GroupByFormattedValue and inform us if the used approach meets your requirements. Do not hesitate to contact us if you have any further inquiries.

Greetings,
Ivan Ivanov
the Telerik team