How to utilize PreviewSelectionChanged effectively?

[Sean]

I am capturing the PreviewSelectionChanged event in my ViewModel successfully. I want to validate data on the page and show a confirmation dialog and cancel the tab change or not depending on the DialogResult. Can I please have an example on how to do this? I can also accomplish this if someone shows me how to access the indices of items in e.AddedItems and e.RemovedItems.

[Hristo]

Hello Sean,

You can take a look at the following movie http://channel9.msdn.com/Events/MIX/MIX11/OPN03 about how to show message box from the view model (at minute 23, there are two approaches you can choose from).

Regarding the indices. Actually in the e.Removed items and e.AddedItems you have the instances of your view model objects. Simply you should check their indices in the collection property you are binding to the RadTabControl.ItemsSource.

Hope this helps.

All the best,
Hristo
the Telerik team