How to change AppointmentStatus in managed Exchange Web Services

Question

I need to change appointment status to meeting, so that it invitations can be send by one click. But Appointment.AppointmentStatus and Appointment.IsMeeeting are read only properties. I've found, using reflector, that PropertyBag class is used for setting and getting items properties, but it's also internal. Can I change this properties somehow?

Answer 1

I manage to do it. Steps are not so simple and logical, but here they are:

var extendedProperty = new ExtendedPropertyDefinition(new Guid("00062002-0000-0000-C000-000000000046"), 0x8217, MapiPropertyType.Integer);
meeting.SetExtendedProperty(extendedProperty, 1);

where Guid is PropertySet of appointments, and that strange number is MeetingStatus property id. And that's all. "Send" button is active by default.