Google Calendar API V3-Event.Recurrence始终为null

Question

I try to create a Calendar Synchronisation between my Application and the Google Calendar.

But now I have a Problem I just can't solve..

I'm getting all Events from the Calendar like this:

EventsResource.ListRequest request = service.Events.List("primary");
request.TimeMin = new DateTime(1990,1,1);
request.ShowDeleted = false;
request.SingleEvents = true;
request.MaxResults = 1000;
request.OrderBy = EventsResource.ListRequest.OrderByEnum.StartTime;

Events events = request.Execute();
foreach(Event ev in events.Items)
{
    String s = ev.Recurrence;//Recurrence is always null
}

But ev.Recurrence is never filled, also when ev.RecurringEventId is filled.

Answer 1

Recurrence property of the Event object is not populated for single events or instances of the recurring event. This is what google is saying about that field:

This field contains list of RRULE, EXRULE, RDATE and EXDATE lines for a recurring event, as specified in RFC5545. Note that DTSTART and DTEND lines are not allowed in this field; event start and end times are specified in the start and end fields. This field is omitted for single events or instances of recurring events.

RecurringEventId property of the Event object is provided, well, for instances of the recurring event. It's not gonna be populated for the non-recurring events.