Ability to validate if there are selected,checked, expanded items, if a node has items

Change the selection on MouseLeftButtonUp instead of MouseLeftButtonDown.

DECLINED: Duplicate with https://feedback.telerik.com/Project/143/Feedback/Details/112812-treeview-perform-selection-on-mouseleftbuttonup

BringIntoView and GetItemByPath are slow on trees with many nested levels (20-30).
In Q2 2014 these methods will be faster in scenarios with TreeView Lines.

Change the SelectedValue implementation to allow a TwoWay binding

RadTreeView is virtualized and SelectionMode is set to "Extended". All ViewModels are selected and IsSelected of TreeViewitems is 2-way bound to IsSelected in the ViewModels. When clicking a TreeViewitem with Mouse, all other items are deselected. However, when scrolling we see that items are being prepared are not deselected - they are still selected.

This is due to a Limitation of the Virtualization mechanism - it does not know about the existance of the ViewModels and does not work with them. Virtualization works only with the Containers - the RadTreeViewItem.

Collapse a RadTreeViewItem when all its children are dragged elsewhere. This is needed in scenarios where the RadTreeViewItem DefaultImageSrc and ExpandedImageSrc properties are set, and you want to revert back to the DefaultImageSrc once all children of the item are dragged to other positions.

Modify the SelectionChanged event logic so that the event is only fired once - exposing both the RemovedItems and AddedItems collections.

Expose properties that controls the lines color and their thickness like in the RadTreeListView.

Add 'None' to the selection mode enum

ExpandAll() is a UI operation which blocks the UI thread.

Expose IsDropBeforeAllowed, IsDropAfterAllowed and IsDropInsideAllowed properties in order to facilitate the implementation of complicated drag/drop scenarios in MVVM scenarios.

Update: The suggested approach would be to use an attached behavior for DragDropManager.DragOverEvent in order to change the default TreeView behavior.
DropAction property of a TreeViewDragDropOptions instance could be used to customize the drop operation.
Also, the DropPosition property of the TreeViewDragDropOptions instance could be used to check current drop case.
An instace of TreeViewDragDropOptions could be retreived from DragOverEvent event arguments.

Improve selection performance.

When IsVirtulizing is set to true and there are many items in the tree view pressing several times PageUp key brings the view port to the beginning of the tree rather to the previous page.

Rendering issues occure when using Hierarchical virtualization mode and bring into view.
The issue is hit in both platforms - WPF and Silverlight. 

When placed in grid column with Auto width and had its own width set to Auto, the RadTreeView does not scroll.

When the TreeView's ScrollViewer is Visible, changing the tree's width to 0 them back to Auto breaks the scrolling function of the ScrollViewer.
The workaround is to make the TreeView Collapsed before setting the Width to 0 and make it Visible before setting the Width back to Auto.

Another workaround: Use visibility instead of Width=0.

SelectedItem property should not accept RadTreeViewItem objects when is data bound.

Reason for decline:

SelectedItems collection does not work correctly when the RadTreeView is virtualized and ContainerBindings (SL) / Style Bindings (WPF) are used for binding the IsSelected property.


The issue is not reproducible with R3 2016 version of RadTreeView with both Multiple and Extended Selection mode.
Please open a new support thread with detals from your scenario if you encounter similar issue.

Setting a non-default value to the RadTreeView ItemsIndent property disarranges the lines

Scenario: Databound TreeView with IsSelected bindings between item and container. Adding a selected data object to the ItemsSource does not fire the Selected event.