Declined
Last Updated: 12 Nov 2019 13:45 by Petar

When a large number of items are selected through extended selection (with a lot of items on the first level of the RadTreeView) the selection does not work correctly. 

Workaround - make the selection in viewmodels manually and provide 2way bindings in style
 <telerik:RadTreeView.ItemContainerStyle>
                <Style TargetType="telerik:RadTreeViewItem">
                    <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
                    <Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
                </Style>
            </telerik:RadTreeView.ItemContainerStyle>
private void SomeRadTreeView_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            int count = e.AddedItems.Count;
            if (count > 1)
            {
                SomeViewModel first = e.AddedItems[0] as SomeViewModel;
                SomeViewModel last = e.AddedItems[count - 1] as SomeViewModel;
                
                this.SomeRadTreeView.SelectionChanged -= this.SomeRadTreeView_SelectionChanged;
                this.SomeRadTreeView.AutoScrollToSelectedItem = false;
                this.ViewModel.SelectRange(first, last);
                this.SomeRadTreeView.AutoScrollToSelectedItem = true;
                this.SomeRadTreeView.SelectionChanged += this.SomeRadTreeView_SelectionChanged;
            }
        }

Declined
Last Updated: 19 Jan 2018 05:47 by wu
with RadTreeView control,using MVVM binding,the xaml like :
AutoScrollToSelectedItem="True"  IsVirtualizing="False"
looking the attach files,Navigate by the  RadBreadcrumb(the RadBreadcrumb and the RadTreeView binding the same data source,and binding the same SelectedIem),
when expand the level4,the RadTreeView  can't bring the selected item to view,but scroll mouse to the seleced item view,then Navigate again the same postion ,it can scroll,the radtreeview can reach the selected item.
     I test the microsoft treeview,if the Virtualizing is true,it can't scroll the selected item,but set the Virtualizing  to false,it is good.
    the other question,how to set the style?the  selected item's highligh area can expand the full row,like the visual studio.
Declined
Last Updated: 21 Dec 2017 12:46 by ADMIN
a) Using WCF RIA Services
b) Using QueryableDomainServiceCollectionView
c) Using TreeView with above two
d) Including LoadOnDemand
e) Using "Prepared Item"
Declined
Last Updated: 09 Jan 2017 15:54 by ADMIN
Created by: Ivar
Comments: 2
Category: TreeView
Type: Bug Report
0
When sorting a table I get the following stacktrace.

06.12.2016 15:39:34 Error General Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
   at System.Windows.Controls.ItemContainerGenerator.Remove(GeneratorPosition position, Int32 count, Boolean isRecycling)
   at Telerik.Windows.Controls.TreeView.TreeViewPanel.CleanupRange(IList children, IItemContainerGenerator generator, Int32 startIndex, Int32 count)
   at Telerik.Windows.Controls.TreeView.TreeViewPanel.CleanupContainers(Int32 firstViewport, ItemsControl itemsControl)
   at Telerik.Windows.Controls.TreeView.TreeViewPanel.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
   at System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
   at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV, Boolean& hasDesiredSizeUChanged)
   at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Controls.Control.MeasureOverride(Size constraint)
   at Telerik.Windows.Controls.RadTreeViewItem.MeasureOverride(Size availableSize)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at Telerik.Windows.Controls.TreeView.TreeViewPanel.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
   at System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
   at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV, Boolean& hasDesiredSizeUChanged)
...
Declined
Last Updated: 04 Jan 2017 12:57 by ADMIN
ADMIN
Created by: Pavel R. Pavlov
Comments: 0
Category: TreeView
Type: Feature Request
0
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
Declined
Last Updated: 29 Dec 2016 14:20 by BHAGWATI
We have a RadTreeView. There is no horizontal scrollbar.
We edit a node's header to a longer string and a horizontal scrollbar appears.
If we edit again the node's header to a shorter string, the horizontal scrollbar remains even it isn't needed anymore.

UPDATE:
There is a similar problem with the height of a RadTreeViewItem.
If we edit the RadTreeViewItem's content to become at least of two lines - the height of the item is increased, which is expected.
But if we re-edit this item's content to be on one line only - the height of the item remains larger, which is incorrect.
Please note, that this issue is observed ONLY on sub-items not on the parent nodes.

This seems not reproducible  with R3 2016 version of RadTreeView.
Please open a new support ticket with details regarding this issue if you encounter it.
Declined
Last Updated: 07 Dec 2016 15:12 by ADMIN
When the FlowDirection is RightToLeft, the vertical lines of the control aren't properly aligned.

The issue is not reproducible with R3 2016 Release.
Declined
Last Updated: 11 Aug 2016 14:04 by ADMIN
When value types are inserted in the Items collection of RadTreeView and root values are duplicated in the children a StackOverflowException is raised after a call to ExpandAll.

The XAML has recently reviewed the status of this issue and won't be addressing it in future releases.
This is a design limitation - RadTreeView does not support duplication of value types in its Items / ItemsSource collections. 
This potentially can cause troubles with virtualization / selection / expandALL features.
Declined
Last Updated: 11 Aug 2016 14:04 by ADMIN
Setting the IsChecked via binding causes synchronization issue with CheckState during initial container creation.

Declined.

IsChecked and CheckState are not supported in binding scenarios. In databinding scenarios use the approach described here.
http://www.telerik.com/help/wpf/radtreeview-howto-tri-state-mvvm.html
Declined
Last Updated: 11 Aug 2016 14:04 by ADMIN
The TreeViewPanel doesn't display the TreeViewItems when the TreeView ItemsPresenter ControlTemplate element is wrapped in a Border or Grid control.

Declined.

Changing the default control template of our controls is risky, every template part has its purpose and usually it is used in code behind. 
We cannot support such template changes to not reflect the main features such as virtualization,scrolling, fast performance.
Declined
Last Updated: 11 Aug 2016 14:04 by ADMIN
Ability to have both static and bound RadTreeViewItems or different hierarchy levels.

Reason for decline: There is no proper way this to be implemented.
 This would require huge refactoring of the DragDrop, Styling, Editing, Virtualization logic. 
Complexity of such task  is close to writing a new control from scratch.
Declined
Last Updated: 11 Aug 2016 14:04 by ADMIN
DataTriggers that apply DefaultImageSrc, ExpandedImageSrc don't work when the TreeView is virtualized.
Reason for deletion:
The workaround is easy - just bind the DefaultImageSrc, ExpandedImageSrc to string properties from the ViewModel.
Also, a possible fix would slow down the virtualization process in the RadTreeView.
Declined
Last Updated: 11 Aug 2016 14:04 by ADMIN
Improve the synchronization between the TreeView.IsOptionElementsEnabled with the TreeViewItem.OptionType property. In a scenario where the TreeViewItem.OptionType property is databound, changing the TreeView.IsOptionElementsEnabled property doesn't respect the databound values of the TreeViewItem.OptionType.
===
Reason for deletion: These  proeprties are marked obsolete.
Declined
Last Updated: 11 Aug 2016 14:04 by ADMIN
ADMIN
Created by: Telerik Admin
Comments: 1
Category: TreeView
Type: Bug Report
13
When TreeView is placed inside floating VS ToolWindow and item is selected the visual state remains unchanged after focus leaves the TreeView.
Declined
Last Updated: 11 Aug 2016 14:04 by David Liebeherr - rent-a-developer
When the RadTreeView is virtualizaed, the images are  not shown. This works when the tree is bound to collection of objects and the DefaultImageSource is bound.

Reason for deletion:
The workaround is easy - just bind the DefaultImageSrc, ExpandedImageSrc to string properties from the ViewModel.
Also, a possible fix would slow down the virtualization process in the RadTreeView.
Declined
Last Updated: 11 Aug 2016 14:04 by ADMIN
Items are lost after reexpanding when TreeView is Virutalized and items are set in XAML.
Currently the TreeView does not support virtualization when using XAML items.

Reason for Decline: Virtualization is not supported in non-databound treeviews.
Declined
Last Updated: 11 Aug 2016 14:04 by ADMIN
When two equal objects are used in the source collection, the first is always selected when you try to select the others.

Workaround when TreeView is not databound.

Instead of adding objects directly in the TreeView's Items Collection, add RadTreeViewItems.
For Example, instead of
 treeView.Items.Add(1), 
treeView.Items.Add(2)

do

 treeView.Items.Add(new RadTreeViewItem(){Header = 1}, 
 treeView.Items.Add(new RadTreeViewItem(){Header = 2}

Workaround when TreeView is databound.

For example , if we databind the treeview to collection of DataItems and some dataitem is located in multiple places in the source collection.
Solution => Wrap the DataItem class in new class - DataItemWrapper. It can hold the underlying DataItem, add additional property  (for exampel ID) and override the Equals and GetHashCode methods.
This way different DataItemWrapper objects can hold equal DataItem objects. In such way if you bind the treeview to collection of DataItemWrappers the selection will be successful.

DECLINED:
The XAML team recently reviewed this bug  and won't be adressing it in future. It can be actually considered as feature request because selection should have notion for selected containers.
Unfortunately, the initial code design of the RadTreeView does not have such notion and the complexity of adding such feature now is very big.
Declined
Last Updated: 19 May 2016 14:43 by ADMIN
RadTreeView with virtualization turned on, defines HierarchicalDataTemplates for its items. 

In the template, the root panel is 32 pixels (or higher than the default TreeViewItemHeight - 24 px in OfficeBlackTheme). Scrolling the treeview, then maximizing the wpf window results in misplaced / incorrect height of treeviewitems.

Possible workaround:
Set the MinHeight property of RadTreeViewItem so that all its header content fits. Then set the item's VerticalConentAlignment to Stretch
        <Style TargetType="telerik:RadTreeViewItem">
                         <Setter Property="MinHeight" Value="48" />
                        <Setter Property="VerticalContentAlignment" Value="Stretch" />
                   </Style>

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.
Declined
Last Updated: 03 Mar 2016 08:55 by Alan
A common request is to have a way to hide the root node of a RadTreeView so that the second-level nodes are displayed without a root.  If the RadTreeView is bound, it appears that this can be done through the hierarchical binding if one know what one is doing.  However, there does not seem to be a simple way to do it if the nodes to be added to the RadTreeView are added programmatically.  It would be helpful if there were a binary property on the RadTeeView to set whether the root node is displayed.


Reason for decline:
Both in databound tree or not , you can add only the items you need to display in the root source / root items collection of the tree. Generally, there is no value of hiding a root node that has children - why is inside the collection at all ?
Declined
Last Updated: 04 Feb 2016 14:56 by ADMIN
The CheckedItems  collection is not cleared when ItemsSource is changed.

Please consider CheckedItems as not supported collection in RadTreeView. In DataBinding scenarios , use the approach described in the following article:
http://docs.telerik.com/devtools/wpf/controls/radtreeview/how-to/howto-tri-state-mvvm.html 
This way you will be able to create CheckedItems property in your ViewModels.

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.
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