MaxSelectedDates Property

using Infragistics.Windows.Editors;
using Infragistics.Windows.Editors.Events;
using Infragistics.Windows.Controls;

        private void InitializeCalendar(XamMonthCalendar calendar)
        {
            // the selectiontype determines how dates may be selected
            // Range is a special type of multiple selection that ignores
            // the control key state and therefore doesn't allow 
            // discontigous sections via the ui
            calendar.SelectionType = SelectionType.Range;

            // use MaxSelectedDates to restrict the number of dates
            // that can be selected
            calendar.MaxSelectedDates = 7;

            // you can add individual dates to the SelectedDates but 
            // when selecting a range, the AddRange method is more
            // convenient
            //
            //calendar.SelectedDates.Add(new DateTime(2008, 10, 14));
            //calendar.SelectedDates.Add(new DateTime(2008, 10, 15));
            //calendar.SelectedDates.Add(new DateTime(2008, 10, 16));
            calendar.SelectedDates.AddRange(new DateTime(2008, 10, 14), new DateTime(2008, 10, 16), true);

            // make the last day in the selection active
            calendar.ActiveDate = new DateTime(2008, 10, 16);

            calendar.SelectedDatesChanged += xamMonthCalendar1_SelectedDatesChanged;
        }

        void xamMonthCalendar1_SelectedDatesChanged(object sender, SelectedDatesChangedEventArgs e)
        {
            StringBuilder sb = new StringBuilder();

            sb.Append("Added:");
            for(int i = 0; i < e.AddedDates.Count; i++)
            {
                if (i > 0)
                    sb.Append(", ");

                sb.Append(e.AddedDates[i].ToString("d"));
            }
            sb.AppendLine();

            sb.Append("Removed:");
            for (int i = 0; i < e.RemovedDates.Count; i++)
            {
                if (i > 0)
                    sb.Append(", ");

                sb.Append(e.RemovedDates[i].ToString("d"));
            }
            sb.AppendLine();

            System.Diagnostics.Debug.WriteLine(sb.ToString(), "SelectedDatesChanged");
        }