EWS create appointment and set specific GlobalObjectId

Hi,

I'm trying to create an appointment in 2 mailboxes and simulate the Auto Answer feature:

userA creates an appoitment with userB as RequiredAttendee and I want userB to automatically accept the appointment.

I have 2 solutions:

Solution 1:

I impersonate userA and create and appointment with the option CalendarItemCreateOrDeleteOperationType.SendToAllAndSaveCopy.

I then open the calendar of userB, locate the calendarEntry by CleanGlobalObjectId, programmatically accept the invitation, and finally delete the mail from the inbox.

This is working fine but I would prefer to make work solution 2:

Solution 2:

I create 2 separate appointments in the 2 calendars and link them with the GlobalObjectId and CleanGlobalObjectId values: I manage to create an appointment in calendar A and retrieve the GlobalObjectId.

When I create a new appointment in calendar 2 and set GlobalObjectId and CleanGlobalObjectId, I get no errors but when I read back the value, it is not the value I tried to set as if Exchange had ignored the value passed and created his own one.

I tried to set the value during creation or during update in vain.

Do you have a sample code that creates an appointment and set the GlobalObjectId ?

Example of creation:

List<ExtendedPropertyType> properties = new List<ExtendedPropertyType>();
properties.Add(CreateExtendedProperty("CleanGlobalObjectId", id, MapiPropertyTypeType.String)); <<--- tried with binary too
properties.Add(CreateExtendedProperty("GlobalObjectId", id, MapiPropertyTypeType.String));
appointment.ExtendedProperty = properties.ToArray();

private ExtendedPropertyType CreateExtendedProperty(string name, string base64String, MapiPropertyTypeType type)
        {            return new ExtendedPropertyType()            {                ExtendedFieldURI = new PathToExtendedFieldType()                {                    PropertyName = name,                    PropertyType = type,                    PropertySetId = "6ED8DA90-450B-101B-98DA-00AA003F1305",                    PropertyId = 0x0023                },                Item = base64String            };        }

Example of update: 

string id = "BAAAAIIA4AB0xbcQGoLgCAAAAACpxe3c0IDOAQAAAAAAAAAAEAAAAAx/fxXSBOlFsIvn9fJnzmc=";
byte[] bytes = System.Convert.FromBase64String(id);
ExtendedPropertyDefinition epd = new ExtendedPropertyDefinition(                            new Guid("6ED8DA90-450B-101B-98DA-00AA003F1305"),                            0x0023, MapiPropertyType.Binary);
appointment.SetExtendedProperty(epd, bytes);
appointment.Update(ConflictResolutionMode.AutoResolve);   

-- Emmanuel Dreux