Accessing calendar items in a recurring series by using the EWS Managed API 2.0

Bind to the calendar item by using its unique identifier. The following code shows how to bind to a calendar item and provide it with connection configuration information by using an ExchangeService object named service. The ItemId has been shortened to preserve readability.

Appointment appointment = Appointment.Bind(service, new ItemId("AAMkA="));

Check the value of the AppointmentType property on the calendar item. The following code shows how to determine the type of the calendar item by using the AppointmentType property.

if (appointment.AppointmentType == AppointmentType.RecurringMaster)
{
   // Calendar item is a recurring master item for a recurring series.
}
else if (appointment.AppointmentType == AppointmentType.Occurrence)
{
   // Calendar item is an occurrence in a recurring series.
}
else if (appointment.AppointmentType == AppointmentType.Exception)
{
   // Calendar item is an exception in a recurring series.
}
else
{
   // Calendar item is not part of a recurring series.
   // The value of appointment.AppointmentType is AppointmentType.Single.
}

Create a search filter. The following code shows how to create a search filter to find items that have a start date on or after January 1, 2009. For more information about how to build search filters, see Working with search filters by using the EWS Managed API 2.0.

SearchFilter.SearchFilterCollection searchFilter = new SearchFilter.SearchFilterCollection();
searchFilter.Add(new SearchFilter.IsGreaterThanOrEqualTo(AppointmentSchema.Start, new DateTime(2009, 1, 1)));

Create an ItemView and specify which properties to return in the result set. The following code shows how to configure a search that will return a maximum of twenty items, each containing the following properties: Id, Subject, Start, and AppointmentType. For more information about how to configure ItemView, see Searching for items in a mailbox by using the EWS Managed API 2.0.

ItemView view = new ItemView(20);
view.PropertySet = new PropertySet(BasePropertySet.IdOnly, AppointmentSchema.Subject, AppointmentSchema.Start, AppointmentSchema.AppointmentType);

Send the request to search the mailbox that is associated with the service binding. The following code shows how to search the Calendar folder by using the search filter and view defined in the previous steps. This example assumes that service is a valid ExchangeService binding.

FindItemsResults<Item> findResults = service.FindItems(WellKnownFolderName.Calendar, searchFilter, view);

Iterate through the search results, checking the value of the AppointmentType property for each item. FindItems returns items having AppointmentType equal to AppointmentType.RecurringMaster and items having AppointmentType equal to AppointmentType.Single; therefore, you must check the value of the AppointmentType property to identify recurring master items.

foreach (Item item in findResults.Items)
{
    Appointment appt = item as Appointment;
    if (appt.AppointmentType == AppointmentType.RecurringMaster)
    {
       // Calendar item is a recurring master item for a recurring series.
    }
}

Create a CalendarView, specify the date range for the search, and specify which properties to return in the result set. The following code shows how to configure a search that will return calendar items that occur between January 1, 2009 and January 31, 2009 (inclusive), with each item containing the following properties: Id, Subject, Start, IsReccuring, and AppointmentType.

DateTime startDate = new DateTime(2009, 1, 1);
DateTime endDate = new DateTime(2009, 1, 31);
CalendarView calView = new CalendarView(startDate, endDate);
calView.PropertySet = new PropertySet(BasePropertySet.IdOnly, AppointmentSchema.Subject, AppointmentSchema.Start, AppointmentSchema.IsRecurring, AppointmentSchema.AppointmentType);

Send the request to search the mailbox that is associated with the service binding. The following code shows how to search the Calendar folder by using the CalendarView that was defined in the previous steps. This example assumes that service is a valid ExchangeService binding.

FindItemsResults<Appointment> findResults = service.FindAppointments(WellKnownFolderName.Calendar, calView);

Iterate through the search results, checking the value of the AppointmentType property for each item. FindAppointments returns items having AppointmentType equal to AppointmentType.Occurrence, items having AppointmentType equal to AppointmentType.Exception, and items having AppointmentType equal to AppointmentType.Single; therefore, you must check the value of the AppointmentType property to identify occurrence items and exception items.

foreach (Appointment appt in findResults.Items)
{
    if (appt.AppointmentType == AppointmentType.Occurrence)
    {
       // Calendar item is an occurrence in a recurring series.
    }
    else if (appt.AppointmentType == AppointmentType.Exception)
    {
       // Calendar item is an exception in a recurring series.
    }
}

Save the start date/time of the occurrence item or exception item that you are interested in. In the following code, occurrenceItemOrExceptionItem is the appointment for which to get the previous appointment and next appointment.

DateTime occurStart = occurrenceItemOrExceptionItem.Start;

Iterate through the appointments in the recurring series, using the value of the Start property to locate the appointment that you are interested in, and finding the previous appointment to and next appointment after that appointment. The following code shows how to iterate through the appointments in a series, identify the appointment that has a Start property value that matches the value that you saved in the previous step, and use the BindToOccurrence method to get the previous appointment and the next appointment in the series. When you reach the end of the series, or try to access an item by using an index that does not exist in the series, you will get an exception with the message "Occurrence Index is out of recurrence range." The following code catches these exceptions and displays the appropriate message. The string sRecurringMasterId represents the ItemId of the recurring master item for the series.

int iCurrentIndex = 1;
try
{
    while (true)
    {
        // Get the appointment that is located at the current index in the series.
        Appointment seriesAppt = Appointment.BindToOccurrence(service, new ItemId(sRecurringMasterId), iCurrentIndex);

        // If the current appointment's Start value matches the item that you are looking for, get the previous item and next item in the series.
        if (seriesAppt.Start == occurStart)
        {
            // Get the previous appointment in the series, if there is one.
            if (iCurrentIndex > 1)
            {
                Appointment priorAppt = Appointment.BindToOccurrence(service, new ItemId(sRecurringMasterId), iCurrentIndex - 1);
            }
            else
            {
                Console.WriteLine("There is no previous appointment in the series.");
            }

            // Get next appointment in the series.
            try
            {
                Appointment nextAppt = Appointment.BindToOccurrence(service, new ItemId(sRecurringMasterId), iCurrentIndex + 1);
            }
            catch (Exception e)
            {
                if (e.Message == "Occurrence index is out of recurrence range.")
                {
                    Console.WriteLine("There is no 'next' occurrence in the series.");
                }
                else
                {
                    throw e;
                }
            }
        }
        iCurrentIndex++;
    }
}
catch (Exception e)
{
    if (e.Message == "Occurrence index is out of recurrence range.")
    {
        Console.WriteLine("The end of the series has been reached.");
    }
    else
    {
        throw e;
    }
}