IndexOutOfRangeException when zero count given

[Jan]

Hi,

im using DataBoundListBox with VirtualizingDataCollection like in this demo code:

XAML

<Controls:RadDataBoundListBox
            x:Name="listBox"
            DataVirtualizationMode="Automatic"
            Grid.Row="1"/>

CODE BEHIND

var col = new VirtualizingDataCollection(0, 10);
listBox.ItemsSource = col;

At first, DataBoundListBox is showing "no data to display" as it should. But when i try to scroll down in this empty list, it gives me IndexOutOfRangeException.

STACKTRACE
   at Telerik.Windows.Data.VirtualizingDataCollection.ProcessIndexesToLoadInAttachedMode(RadVirtualizingDataControl control)
   at Telerik.Windows.Data.VirtualizingDataCollection.MakeDataRequestIfNeeded(Int32 pivotIndex)
   at Telerik.Windows.Data.VirtualizingDataCollection.OnAttachedListBox_ScrollStateChanged(RadVirtualizingDataControl sender, ScrollState oldState, ScrollState newState)
   at Telerik.Windows.Controls.RadVirtualizingDataControl.OnScrollStateChanged(ScrollState oldState, ScrollState newState)
   at Telerik.Windows.Controls.RadDataBoundListBox.OnScrollStateChanged(ScrollState oldState, ScrollState newState)
   at Telerik.Windows.Controls.RadVirtualizingDataControl.SetScrollState(ScrollState newState)
   at Telerik.Windows.Controls.RadVirtualizingDataControl.OnScrollingStates_StateChanging(Object sender, VisualStateChangedEventArgs e)
   at MS.Internal.CoreInvokeHandler.InvokeEventHandler(Int32 typeIndex, Delegate handlerDelegate, Object sender, Object args)
   at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName)

Thanks for your help,

Jan

[Tsvyatko]

Hi Jan,

Thank you for reporting this issue. We have managed to isolate this issue and we will address it in our next official release for WP8. The issue occurs only if the collection is empty if you do not assign ItemsSource or add ItemsSource with data it will work as expected. (In order to avoid this issue you can use cocepts used in this article - http://www.telerik.com/help/windows-phone/raddataboundlistbox-features-datavirtualization-automatic.html)
 

Regards,
Tsvyatko
Telerik

P.S. I have update your telerik points accordingly.