Issue Deleting Appointments Programmatically

[Matias]

Hi

I'm having an issue trying to delete appointments programmatically. What I'm doing is handling the AppointmentAdded Event and contrasting the appointment subject (which will contain someones name) against a DB. If the appointment subject (Name) does not appear in the aforementioned DB, then the appointment must be deleted. The problem is that the appointment refuses to be deleted.

Here's the code that I'm using:

Private Sub RadScheduler1_AppointmentAdded(sender As Object, e As Telerik.WinControls.UI.AppointmentAddedEventArgs) Handles RadScheduler1.AppointmentAdded
      Dim app As AppointmentWithPhone = TryCast(e.Appointment, AppointmentWithPhone)

      If NameExistsInDB(app.Subject) = False Then
          Debug.WriteLine("Before: " & RadScheduler1.Appointments.Count)

          Me.RadScheduler1.Appointments.Remove(app)

          Debug.WriteLine("After: " & RadScheduler1.Appointments.Count)
      End If
  End Sub

The output in both debug cases is the same. If I have two appointments and add a third with a name that does not exist in the DB (thus forcing my application to enter inside the "IF") I get this:

Debug output:
Before: 3
After: 3

Can you help me out? Am I doing it the right way or is there some other way to delete an appointment?
Thanks!

[Matias]

Well, I managed to solve the issue, but I think the solution works only for my scenario or a similar one.

Here's what I did:
I handled the CollectionChanging event, and filtered the newly added appointment using the NotifyCollectionChangedAction.Add property.

So, the whole code ended up like this:

Private Sub Appointments_CollectionChanging(sender As Object, e As NotifyCollectionChangingEventArgs)
    If e.Action = NotifyCollectionChangedAction.Add Then
        For Each app As AppointmentWithPhone In e.NewItems
            If NameExistsInDB(app.Subject) = False Then
                e.Cancel = True
            End If
        Next
    End If
End Sub

I'm OK with this, however, my question persists. Why is that my other method didn't work?
Thanks again!

[Ivan Petrov]

Hello Matias,

Thank you for writing.

I tried to reproduce the issue you are experiencing with the first method but I was unable to do so. On my machine the appointment was removed every time. I noticed you are using a custom appointment, if you can provide more information on what appointments objects you are using I will be able to investigate the case further.

Nevertheless, your second approach is the better solution in this case. It is better to do not add the appointment in the collection at all, than to add it an remove it.

I hope this helps. Do not hesitate to write back with any further questions.

All the best,
Ivan Petrov
the Telerik team

[Matias]

Hi Ivan,

I'm not getting it, what do you mean by "appointment objects"? Can you please be more specific?
I'm using a custom appointment, but it looks exactly like the one you provide in the tutorial, AppointmentWithPhone (Just a phone field).

The appointment is created by Drag&Drop from a GridView using the code provided in the Drag&Drop example. Also, I give some format to the appointment (Background color, Shape, and so), and to persist it into my DB I handle the CollectionChanged event.

I will be happy to provide more details, just not getting what you mean by "appointment objects".

I look forward to your answer!
Thanks again!

 - Matias

[Ivan Petrov]

Hello Matias,

Thank you for writing back.

I was referring to the AppointmentWithPhone when I wrote "appointment object". This was the only thing I did not use in my test. Nevertheless, I tested the case again using the AppoinemtnWithEmail from our online help but still the result was the same. The remove worked as expected. I would kindly ask you to send me your project so I can investigate this further.

Looking forward to your reply.

Regards,
Ivan Petrov
the Telerik team

[Matias]

Hi Ivan,

Thanks for answering. I'm glad to tell you that I managed to solve the issue. It seems it was related to an error introduced by myself in the code for automatically saving the collection once modified.

Thank you very much for your help on this, keep up the great work you guys are doing!
 - Matias

[Ivan Petrov]

Hi Matias,

I am happy to hear that this issue is sorted out. Should you have any other questions, feel free to contact us.

Kind regards,
Ivan Petrov
the Telerik team