I am binding the IsChecked property to a property in my ViewModel with the help of ItemContainerStyle.
When I click on the checkbox of a child "Item 2", I get the following result:
- Group A
Item 1
x Item 2
So Group A is marked as indeterminate correctly.
When I set Item2.IsChecked = true in my ViewModel, Item2 is marked as checked, but GroupA is marked as unchecked.
Am I doing something wrong? If not, is there a workaround for this?
Best Regards, Matthias
5 Answers, 1 is accepted
Probably you are not doing anything wrong. Keep in mind first that it is better to use CheckState instead of IsChecked in these situations. You can examine this blog post which describes the differences in these properties. On the other hand, there is an unimplemented feature that we plan to implement after the official Q2 2011 ( mid- July). You can examine it and vote for it here. Currently when using Style Bindings (WPF)/ ContainerBindings (SL) you have to implement your TriStateLogic on your own.
Please let us know if you need more info on this.
All the best,
Petar Mladenov
the Telerik team

Yes, this feature is still not implemented in the RadTreeView. You can track its status and vote for it in the mentioned PITS link.
All the best,Petar Mladenov
the Telerik team
Thank you for being the most amazing .NET community! Your unfailing support is what helps us charge forward! We'd appreciate your vote for Telerik in this year's DevProConnections Awards. We are competing in mind-blowing 20 categories and every vote counts! VOTE for Telerik NOW >>

Will it be fixed in next release?
We cannot currently say when this will be implemented. In order to workaround this, you can implement your own TriState logic in the ViewModels and turn off the default ( IsInTriStateMode = false). You can find a good approach realized in this code library project. Please let us know if this is suitable for you.
Greetings,Petar Mladenov
the Telerik team
Thank you for being the most amazing .NET community! Your unfailing support is what helps us charge forward! We'd appreciate your vote for Telerik in this year's DevProConnections Awards. We are competing in mind-blowing 20 categories and every vote counts! VOTE for Telerik NOW >>