Another Drag/Drop ScheduleView fail

[Saul Scudder]

i am using The latest release of Telerik controls. This problem began with the Q2 release. it occurs when draging a simple extended Appointment from a list box to scedule view. I had a version working that implemented a behavere for the list box that worked for q1. I have modified tour code to use the same methods as the telerik example at. http://www.telerik.com/help/silverlight/dragdropmanager_-howto-drag-between-radscheduleview-and-listbox.html. That example program works when run by itself  (and also works when I add my extended Appointment class), When I implement the same methods in our code I get the identical exception as I did with the behavure class we had that started with the new release. The exception (below) is far down into the drag/drop. It there somthing obvious I am missing? How should I proceed?

Value cannot be null.

Parameter name: source

 

   at System.Linq.Enumerable.Count[TSource](IEnumerable`1 source)

   at Telerik.Windows.Controls.CollectionExtensions.HaveSameElementsAsSet[T](IEnumerable`1 c1, IEnumerable`1 c2)

   at Telerik.Windows.Controls.DragDropHelper.<GetHighlightSlotsForDrop>d__d.MoveNext()

   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)

   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)

   at Telerik.Windows.Controls.DragDropHelper.GetDestinationSlotsForDrop(DragDropState state, IEnumerable`1 sourceResources, Point relativeDestinationPoint, TimeSpan offsetFromAppointment)

   at Telerik.Windows.Controls.DragDropHelper.GetDestinationSlots(DragDropState state, Point& relativeDestinationPoint, IPayload payload)

   at Telerik.Windows.Controls.DragDropHelper.GetDestinationSlots(DragDropState state, Point relativeDestinationPoint, IPayload payload)

   at Telerik.Windows.Controls.DragDropHelper.GetDestinationSlots(Object data, Point relativeDragPoint)

   at Telerik.Windows.Controls.DragDropHelper.OnDragOver(Object sender, DragEventArgs e)

   at Telerik.Windows.DragDrop.DragEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)

   at Telerik.Windows.RadRoutedEventArgs.InvokeHandler(Delegate handler, Object target)

   at Telerik.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RadRoutedEventArgs routedEventArgs)

   at Telerik.Windows.RouteItem.InvokeHandler(RadRoutedEventArgs routedEventArgs)

   at Telerik.Windows.EventRoute.InvokeHandlersImpl(Object source, RadRoutedEventArgs args, Boolean raisedAgain)

   at Telerik.Windows.EventRoute.InvokeHandlers(Object source, RadRoutedEventArgs args)

   at Telerik.Windows.RadRoutedEventHelper.RaiseEvent(DependencyObject element, RadRoutedEventArgs args)

   at Telerik.Windows.DependencyObjectExtensions.RaiseEvent(DependencyObject element, RadRoutedEventArgs e)

   at Telerik.Windows.DragDrop.DragOperation.RaiseDragEvent(RoutedEvent dragEvent, DependencyObject target)

   at Telerik.Windows.DragDrop.DragOperation.OnDragOver(DependencyObject sender)

   at Telerik.Windows.DragDrop.DragOperation.DoDragOver(DependencyObject currentTarget)

[Valeri Hristov]

Hi Saul,

Could you please, check the following forum thread for a new, improved way to get ListBox-ScheduleView drag-drop:
http://www.telerik.com/community/forums/silverlight/scheduleview/listbox-drag-drop-behavior.aspx

Kind regards,
Valeri Hristov
the Telerik team