Drag and drop from list box to RadSchedule view through commands

[bonDaviD]

Hi,

I am trying to implement the drag and drop functionality between the RadScheduleView and listbox. I have followed the samples provided by telerik to implement the task. I have a converter named "ScheduleViewToAppointmentConverter" and also ScheduleVIewDragDropBehaviour class to implement the custom drag drop behaviour. In the Beaviour class i have override the Drop method and there i got my custom appointment Deal though State. And i can add it to the destination source and the new dragged item will be displayed in my schedule view. The code snippet for the behaviour class is as follow . Here eventhogh i get the dragged data in the drop menthod i coudnt communicate with the view model.

public class ScheduleViewDragDropBehavior : Telerik.Windows.Controls.ScheduleViewDragDropBehavior
   {
       public override IEnumerable<IOccurrence> ConvertDraggedData(object data)
       {
           if (DataObjectHelper.GetDataPresent(data, typeof(Deal), false))
           {
               return ((IEnumerable)DataObjectHelper.GetData(data, typeof(Deal), false)).OfType<IOccurrence>();
           }
           return base.ConvertDraggedData(data);
       }


       public override void Drop(Telerik.Windows.Controls.DragDropState state)
       {
           if (state.SourceAppointmentsSource == state.DestinationAppointmentsSource)
           {
               base.Drop(state);
           }
           else
           {
               var appointmentToAdd = state.Appointment as Deal;
               appointmentToAdd.Subject = "Boney";
               appointmentToAdd.Start = state.DestinationSlots.First().Start;
               appointmentToAdd.End = state.DestinationSlots.First().End;
               (state.DestinationAppointmentsSource as ObservableCollection<Deal>).Add(appointmentToAdd);
           }
       }

   }

Here Deal is my custom appointment class.

Now i want to implement the drag and drop through commands, so that i can get the dragged data in the view model  and from there I can assign it to the appointment collection for binding to schedule view after checking some validations. How can i implement the drag and drop though commands.?

Also i  have 2  resource named "Main" and "Side" in the schedule view. If i am dragging it main ,  I have check whether the any appointment already exists there , if so drop cannot happen So which is the best place to implement these kind of validations .

[Valeri Hristov]

Hi,

Regarding the drag-drop with commands: you could create ICommand dependency properties on your custom drag-drop behavior (it is a DependencyObject) and bind them to the corresponding properties in the ViewModel. The behavior inherits the data context of RadScheduleView so the binding should not be a problem.

As for the validation, I would recommend using the CanDrop method of the drag-drop behavior - if you return false the cursor will change accordingly and the experience will be consistent.

Kind regards,
Valeri Hristov
the Telerik team