Create Appointment - Frequency Weekly by Code?

[ITA]

Hi,

I'm not able to create an appointment with a frequency like weekly by c# Code! No error but the appointment is not shown in
the scheduleview! Why?

I'm using WPF RadControls 2012 Q1 SP1 and c# .Net 4.0

foreach (DataRow tasks_dr in passw_dt.Rows)
    {
        DateTime start = Convert.ToDateTime(tasks_dr.Field<String>("StartDatum"));

         switch (start.DayOfWeek)
          {
              case DayOfWeek.Saturday:
                     start = start.AddDays(2);
                     break;
               case DayOfWeek.Sunday:
                      start = start.AddDays(1);
                       break;
           }

           TimeSpan duration = TimeSpan.FromDays(5);
            DateTime end = Convert.ToDateTime(tasks_dr.Field<String>("Enddatum"));
            switch (end.DayOfWeek)
            {
                case DayOfWeek.Sunday:
                     end = end.AddDays(-1);
                      break;
                 case DayOfWeek.Monday:
                      end = end.AddDays(-2);
                      break;
              }

              Appointment appointment = new Appointment
               {
                   Start = start,
                   Url = Convert.ToString(tasks_dr.Field<Int64>("id") + "#" + tasks_dr.Field<String>("Betreuer")),
                   End = end,
                   Subject = tasks_dr.Field<String>("Subject"),
                   Body = tasks_dr.Field<String>("Body"),
                   Importance = GetImportance(tasks_dr.Field<String>("Importance"))
                };

                if (tasks_dr.Field<String>("Kategorie") == "Fertig")
                {
                    appointment.Category = this.Categories[0];
                }
                else if (tasks_dr.Field<String>("Kategorie") == "in Arbeit")
                {
                    appointment.Category = this.Categories[1];
                }
                else
                {
                    appointment.Category = this.Categories[2];
                }

                if (tasks_dr.Field<Int64>("Ganztag") == 0)
                {
                    appointment.IsAllDayEvent = false;
                }
                else
                {
                    appointment.IsAllDayEvent = true;
                }

                var Pattern = new RecurrencePattern();
                Pattern.Frequency = GetFreuqency(tasks_dr.Field<String>("Frequency"));

                if (Pattern.Frequency != RecurrenceFrequency.None)
                {
                    Pattern.DayOrdinal = Convert.ToInt32(tasks_dr.Field<Int64>("DayOridnal"));
                    Pattern.DaysOfWeekMask = GetDay(tasks_dr.Field<String>("DaysofWeekMask"));
                    Pattern.FirstDayOfWeek = GetFirstday(tasks_dr.Field<Int64>("FirstDayOfWeek"));
                    Pattern.Interval = Convert.ToInt32(tasks_dr.Field<Int64>("Interval"));
                    Pattern.MaxOccurrences = Convert.ToInt32(tasks_dr.Field<Int64>("MaxOccurrences"));
                    Pattern.MonthOfYear = Convert.ToInt32(tasks_dr.Field<Int64>("MonthofYear"));
                    Pattern.DayOfMonth = Convert.ToInt32(tasks_dr.Field<Int64>("DayofMonth"));

                    System.DateTime? RecursUntil_d;
                    if (tasks_dr.Field<String>("RecursUntil") != "")
                    {
                        RecursUntil_d = Convert.ToDateTime(tasks_dr.Field<String>("RecursUntil"));
                    }
                    Pattern.RecursUntil = RecursUntil_d;

                    appointment.RecurrenceRule = new RecurrenceRule(Pattern);
                }
                this.appointments.Add(appointment);

Every appointment withput a freqeuncy is shown fine. Thanks
Rgards
Rene