Error: Cannot modify the Items collection when the GraphSource is set

[Nikituki]

Hello,

I'm trying to use RadDiadram control like at this example:
http://www.telerik.com/help/silverlight/raddiagram-data-databinding.html

All works good, but when user try to edit diagram, IE crash with error "Error: Cannot modify the Items collection when the GraphSource is set". Screen with error in attachments.

[Alex Fidanov]

Hello,

You are trying to modify the Items collection, while you should be using the GraphSource instead. You have to add items (nodes or links) in the graph source and not in the RadDiagram.Items. If you are trying to edit the diagram through its UI, then this is not supported with the beta release. However, for Q2 (the official release) we have prepared a bi-directional MVVM mechanism that allows this. If you modify the diagram through the UI, it will notify the GraphSource that a new item has to be created, added or removed from it. Stay tuned for this.

Kind regards,
Alex Fidanov
the Telerik team