When a child item from a RadTreeView is selected and then the selection is changed to any of the parents of this item, the FocusVisual (the dotted border) stays on the child item. Available in LIB version: 2016.1.21
I have tried with the example with 1 million items. The RadTreeView hangs when select 50 and deselect them after.
The AddedItems in the SelectionChanged handler contains an empty object in some cases when the virtualization is enabled and the virtualization mode is set to Hierarchical.
The expanding of items does not work as expected in a data binding scenario when the CollapseAll()/ExpandAll() methods are used There is a scenario where the RadTreeView is data bound and its items IsExpanded property is bound to a property from the view model. Then the CollapseAll() and ExpandAll() methods are called. When you try to collapse the treeview items through the property from their view model (that is bound to IsExpanded) only the items in the view port are collapsed.
Setting the EnhanceTabNavigation to False workarounds the issue in some scenarios. telerik:TreeViewAdvancedSettings.EnhanceTabNavigation="False"
ArgumentException is thrown when TreeView becomes visible on a touch device
This issue is applicable to Silverlight ONLY! We have a RadTreeView with following properties IsLoadOnDemandEnabled="True", IsVirtualizing="True" and SelectionMode="Extended" set. We select an element, collapse his parent and select another item. At this point if we expand the previously parent, both the newly selected item and the the first selected item are selected. It is not correct the first item to preserve its selection state. Duplicate item: https://feedback.telerik.com/Project/143/Feedback/Details/114202-treeview-radtreeviewitem-preserve-its-selection
When we drag and drop an Item of the RadTreeView out of the tree, the VisualState of the item stays mouse over. Even if we click or drag other items, the only way to reset the VisualState of the item is to mouse over it. This can be observed in Silverlight's Theming demo. =============== Resolution: The issue can be easily solved by setting telerik:TreeViewSettings.DragDropExecutionMode="New". This will be the default setting in future releases.
Silverlight only bug. TreeView is bound to observable collection of strings. Theme is changed. Then 10 times is done (remove + add) operation in the source collection. IndexOutOfRangeException is thrown in Set method of IndexTree.cs.
When a RadTreeView with lot of items (800+) is placed in an Accordion from the Microsoft Silverlight Toolkit, there is a performance issue. More specifically when we try to collapse the accordion, the application freezes for few seconds. Also note that the IsVirtualization property is set to True. The XAML team has recently reviewed this issue and will not be addressing it as at this time the team is focusing on the bugs impacting the highest number of developers. If you have encountered this issue and it is blocking for your work please contact us through the support ticketing system with details on your setup and a reference to this item.
Subscribing for the touch event ahndling in OnApplyTemplate might cause mermmory leaks or misfunction. Example - TreeView is first RadTabItem of TabControl. After several tabs pressing, the touch will not work - it is unregistered on Unloaded but it is not registered second time because OnApplyTemplate does not fire second time.
TreeView with virtualization in SL. After ExpandAll and BringPathIntoView (or GetItemBypath / SelectItemByPath), a LayoutCycle exception occurs.