EWS: Access shared calendars

Question

I am trying to use Exchange Web Services to access calendar data, but I can't seem to figure out how to access calendars which have been shared by other users when it is not their default calendar. Assuming another user in my company created a shared calendar and shared it with me, I can't even find the calendar folder, let alone get the items within it.

The answers can be in terms of the EWS Managed API (version 1.0 or 1.1), the service objects directly, or even just the XML body of the SOAP message that needs to be sent to the server. I just need some kind of starting point. Any help would be greatly appreciated.

Answer 1

Here's how I managed to do it:

Dim _cal As New Microsoft.Exchange.WebServices.Data.FolderId(Microsoft.Exchange.WebServices.Data.WellKnownFolderName.Calendar, New Microsoft.Exchange.WebServices.Data.Mailbox(_otherAddress))
Dim _calendarView As New Microsoft.Exchange.WebServices.Data.CalendarView(_startTime.Date, _endTime.Date.AddDays(1))

For Each appointmentItem As Microsoft.Exchange.WebServices.Data.Appointment In _
    service.FindAppointments( _
    _cal, _
    _calendarView)
Next

Note: this only works for the default calendar as that is all I needed for my requirements

Edit: For non-default calendars, have you looked into the ExchangeService.FindFolders method, I have not tried but this might not require root inbox access.

Answer 2

This is rather complicated, because you need the FolderId of the folder in question. In addition to access to the calendar folder you'll need read access to the root folder of the mailbox. This allows you to execute a FindFolder operation to retrieve that id.

Answer 3

I know it's a couple of years after the original post, but just to help people with similar problems, look at this.

It uses the EWS API's WellKnownFolderName.PublicFoldersRoot to access the public folder and browses to the requested subfolder using FolderId's.