[Solved] Error when setting RadTreeViewItem.IsSelected = true

[Phil Cockfield]

I'm doing the following on the TreeView control:

        private void SetSelectedItemOnControl(ITreeNode item)
        {


            var treeItem = treeView.ItemContainerGenerator.ContainerFromItem(item) as RadTreeViewItem;
            if (treeItem != null) treeItem.IsSelected = true;

        }

This successfully retrieves the 'treeItem' node (a RadTreeViewItem).

The next line however, when I set treeItem.IsSelected = true fails with the error:

     ArgumentException

     Value does not fall within the expected range.

Any ideas why?  In testing around with this, I can do other things on that item, like set toggling it's IsExpanded property successfully.  So it's in the visual tree, and seemingly functioning.

What to do?  Thanks!

[Phil Cockfield]

Hello?  Is there a solution to this?

I've tried doing it via data-binding (using details from this post: http://www.telerik.com/community/forums/silverlight/treeview/setting-quot-isexpanded-quot-on-templated-node.aspx) and I'm getting the same 'ArgumentException' error.

     ArgumentException

     Value does not fall within the expected range.

Thanks for any help you can give!!!

[Valentin.Stoychev]

Hi Phil Cockfield,

Can you send us a simple project where this can be observed. You can open a support ticket and attach it there.

Thanks!

Greetings,
Valentin.Stoychev
the Telerik team

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[Phil Cockfield]

OK - figured this out whilst extracting it out into a test project.  Not a problem with the control (opps).

I was trying to make this call before the control had fully loaded into the Visual Tree.  There must be a 'TransformToVisual' call somewhere in the changing of "IsSelected" - which requires the control to be loaded within the visual-tree...and that was the error.

Understand what's going on now.  Sorry for the confusion.  Thanks!