How to get shared calendars using EWS

Question

Hi,
I want to monitor all calendars shared to a user via EWS. I know how to do this provided I know each of the user names. But I don't. So I need to get a list of all the users that have shared their calendar to one specific user. But how? I've searched around.
Is it possible?
If this is indeed not possible; is there a way to list all users? That way should be able to figure out which of them have shared their calendar with 'my' user, by trial and error if nothing else.
Thank you and best regards,
babu

Answer 1

There is no direct way to do this however you can enumerate the Shared Calendar folders a user has added by enumerating the Nav links in the Common Views folder see
http://msdn.microsoft.com/en-us/library/ee157359(v=exchg.80).aspx. You can then get the Mailbox this link refers to use the PidTagWlinkAddressBookEID and extracting the X500 address
from that property. The you can just bind to each of the Folders using that information.
eg
static Dictionary<string, Folder> GetSharedCalendarFolders(ExchangeService service, String mbMailboxname)
Dictionary<String, Folder> rtList = new System.Collections.Generic.Dictionary<string, Folder>();
//GetSharedContacts
FolderId rfRootFolderid = new FolderId(WellKnownFolderName.Root, mbMailboxname);
FolderView fvFolderView = new FolderView(1000);
SearchFilter sfSearchFilter = new SearchFilter.IsEqualTo(FolderSchema.DisplayName, "Common Views");
FindFoldersResults ffoldres = service.FindFolders(rfRootFolderid, sfSearchFilter, fvFolderView);
if (ffoldres.Folders.Count == 1)
PropertySet psPropset = new PropertySet(BasePropertySet.FirstClassProperties);
ExtendedPropertyDefinition PidTagWlinkAddressBookEID = new ExtendedPropertyDefinition(0x6854, MapiPropertyType.Binary);
ExtendedPropertyDefinition PidTagWlinkFolderType = new ExtendedPropertyDefinition(0x684F, MapiPropertyType.Binary);
ExtendedPropertyDefinition PidTagWlinkGroupName = new ExtendedPropertyDefinition(0x6851, MapiPropertyType.String);
psPropset.Add(PidTagWlinkAddressBookEID);
psPropset.Add(PidTagWlinkFolderType);
ItemView iv = new ItemView(1000);
iv.PropertySet = psPropset;
iv.Traversal = ItemTraversal.Associated;
SearchFilter cntSearch = new SearchFilter.IsEqualTo(PidTagWlinkGroupName, "Other Calendars");
FindItemsResults<Item> fiResults = ffoldres.Folders[0].FindItems(cntSearch, iv);
foreach (Item itItem in fiResults.Items)
try
object GroupName = null;
object WlinkAddressBookEID = null;
if (itItem.TryGetProperty(PidTagWlinkAddressBookEID, out WlinkAddressBookEID))
byte[] ssStoreID = (byte[])WlinkAddressBookEID;
int leLegDnStart = 0;
String lnLegDN = "";
for (int ssArraynum = (ssStoreID.Length - 2); ssArraynum != 0; ssArraynum--)
if (ssStoreID[ssArraynum] == 0)
leLegDnStart = ssArraynum;
lnLegDN = System.Text.ASCIIEncoding.ASCII.GetString(ssStoreID, leLegDnStart + 1, (ssStoreID.Length - (leLegDnStart + 2)));
ssArraynum = 1;
NameResolutionCollection ncCol = service.ResolveName(lnLegDN, ResolveNameSearchLocation.DirectoryOnly, true);
if (ncCol.Count > 0)
FolderId SharedCalendarId = new FolderId(WellKnownFolderName.Calendar, ncCol[0].Mailbox.Address);
Folder SharedCalendaFolder = Folder.Bind(service, SharedCalendarId);
rtList.Add(ncCol[0].Mailbox.Address, SharedCalendaFolder);
catch (Exception exception)
Console.WriteLine(exception.Message);
return rtList;
Cheers
Glen