SelectionMode="Extended" implicated in crash during keyboard navigation of hierarchy leaf items to grid cells

[Simon]

Hi there,

This is a bug report.  I think I may have come across a problem in the RadTreeListView control while navigating the cells using the keyboard arrow keys.

Problem Context (may not be relevant):  RadTreeListView with several columns, column 0 being a hierarchy column.  The control's ItemSource is bound to an EntitySet<T> containing a self-referencing hierarchy, so T has a property called Children, made up of further T's:

<telerik:RadTreeListView.ChildTableDefinitions>
  <telerik:TreeListViewTableDefinition ItemsSource="{Binding Children}" />
</telerik:RadTreeListView.ChildTableDefinitions>

The XAML header for my RadTreeListView is:

<telerik:RadTreeListView x:Name="RBSTreeListView1"

  AutoGenerateColumns="False"
  CanUserFreezeColumns="False"
  GridLinesVisibility="Both"
  RowIndicatorVisibility="Collapsed"
  HorizontalAlignment="Left"
  VerticalAlignment="Bottom"
  Height="Auto"
  MaxHeight="700"
  EnableRowVirtualization="True"
  ScrollViewer.HorizontalScrollBarVisibility="Auto"
  ScrollViewer.VerticalScrollBarVisibility="Auto"
  HierarchyExpandButtonStyle="{StaticResource st}"
  HierarchyColumnIndex="0"
  SelectionUnit="Cell"
  SelectionMode="Extended"
>

With SelectionMode="Extended" attribute present, and moving the cell selection around with the arrow keys, I experience the following unhandled exception when navigating from one of the hierarchy leaf nodes on the left side of the control (in column 0), back to a grid cell (in column 1) of the same row:

    Code 4004
    Category: ManagedRuntimeError
    Message: 'System.ArgumentNullException: Value cannot be null.'
    Parameter name: key

When I remove the SelectionMode="Extended" XAML attribute, I no longer experience this unhandled exception.

(Point #2... a related side note:  When SelectionMode is not specified and while navigating around the control's grid with the keyboard, any attempt to move from a hierarchy leaf node cell to a regular (non-hierarchy) cell to its right is blocked.  The same is not true if a rightwards move occurs from a hierarchy node that has children.  Why is this so?)

[Yordanka]

Hi Simon,

Thank you for the feedback.
We are aware of the pointed problems but unfortunately, they are still not addressed. We'll do our best to fix them in one of the next builds.

Excuse us for the inconvenience caused.
 
Kind regards,
Yordanka
the Telerik team

[Simon]

Hello Yordanka,

Thank you for your reply.  I had looked on Telerik's Public Issue Tracking System (http://www.telerik.com/support/pits.aspx) in the Rad Controls for Silverlight area before posting about this problem here.  I did not find a ticket there there that tracked this problem.

Would you be so kind as to post the Issue ID in Telerik's PITS where I can follow the status / progress on this?  Or a URL to the PITS item would even be better. :)

Much appreciated,

Simon

[Vanya Pavlova]

Hi Simon,

 

The PITS ID of this bug is 2841 and you may track its progress following this link.

Best wishes,
Vanya Pavlova
the Telerik team

[Simon]

Thank you very much for the PITS ID and link.  I had a look at the issue there but noticed that it is specific to a Ctrl-RightArrow navigation, and nowhere in the context does it mention the involvement of the SelectionMode="Extended" attribute.  There may, in fact, be two different but somehow related issues.  Perhaps I'll add this context in the issue comments in PITS.