The items of the RadTreeView control do not behave correctly in a touch scenario when expanding/collapsing them.
A possible workaround for this behavior would be to set the TouchManager.ShouldSuspendMousePromotion attached property to True on the RadTreeView control instance.
Dear Telerik team,
We currently have a problem with the RadDragAndDropManager as we are currently in the process of converting from Silverlight to WPF.
We are also converting Telerik from version 2011.2 to the current version of Telerik WPF.
Now the following error happens:
If I drag an item and drag it over another dropable area, the DragCue element moves.
The error occurs as soon as "e.QueryResult" is set to true in the OnDropQuery function.
You just have to do that, otherwise the drop will not be evaluated.
I was able to recreate the whole thing in a new project with just a RadTreeView and a RadMap.
I just don't want to switch the RadDragAndDropManager to the DragDropManager because we have a lot of our own controls that run with the old one, but not with the new one.
I've already tried that, but the conversion effort is just too big.
Can you see why the DragCue element is acting so weird?
With best regards
Markus Kuhlemann
TreeView is in dropdowncontent of a DropDownButton. BringPathIntoView is called on loaded of the button (or the tree). It tries to bring several nested levels deep for example item 90.3.2.1 (4 levels deep).
On opening the button , the scrollviewer is not scrolled to the desired item.
Posssible workarounds:
- invoke the BringPathIntoView method in a Dispatcher.BeginInvoke call
- disable the treeview animations before the call and enable them after the call ( telerik:AnimationManager.IsAnimationEnabled = False)
Hi,
I found a bug when drag&dropping selected tree nodes (extended multi-selection) when the tree is virtualized. Items that never got into view are missing from the Payload Manager Data object. If virtualization is off, works as expected.
Please see modified sample for demonstration. I added 200+ items to League A -> Division A. Select the first item, quickly scroll by dragging vertical scrollbar to the bottom of the list and extend selection to the whole list. Then perform drag and drop. Note, not all items were moved.
Also, the drag visual helper moves and updates very very slowly when dragging hundredths of objects. In our application, we have thousands of objects, which makes it unusable
Thank you for a quick fix.
Tomas.
Select nested item in virtualized treeview with single selection mode.
Collapse its parent. Select item in the level of the parent. Expand the parent and notice two items are visually selected.
Expexted : only the last selected item with mouse should be visually selected.
Workaround:
private void TreeView_ItemPrepared(object sender, RadTreeViewItemPreparedEventArgs e)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.
Select an item with mouse, scroll thousands of items down and then shift select item to perform range selection. This will block the UI thread for seconds.
When you reorder the collection very fast an exception is thrown. This is reproducible when the UI virtualization is enabled with its virtualization mode set to Recycling, and an item is selected. Also, you can observe some missing items glitches instead of the exception. To reproduce this you can call the ObservableCollection's Move() method several times in a single method (see the attached project). In this case also a NullReferenceException is thrown sometimes instead of the InvalidOperationException. To work this around delay the reordering calls so that the treeview has time to properly measure and arrange itself. For example: Items.Move(10, 2); Application.Current.Dispatcher.BeginInvoke(new Action(() => { Items.Move(10, 2); }), System.Windows.Threading.DispatcherPriority.Background);
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.
When expanding all items with a horizontal scrollbar the last item is hidden by the scrollbar. As a workaround, you can set the IsVirtualizing property of the RadTreeView to True.