Get Outlook AppointmentItem using GlobalAppointmentID

Question

I am developing a calendar for my firm that synchronizes with Outlook Calendar.

Atm I can:

• import appointments from Outlook and show them in my calendar
• update my appointments when Outlook appointments get updated
• create Outlook appointments when appointments get created in my calendar

The only issue I have is updating/deleting Outlook appointments when my appointments update/delete.

I have the GlobalAppointmentID of the corresponding appointments but I can't seem to search on that ID.

I tried:

using Microsoft.Office.Interop;

private void GetAppointment(string myGlobalAppointmentID)
{
Outlook.Application oApp = new Outlook.Application();

Outlook.NameSpace mapiNamespace = oApp.GetNamespace("MAPI");

Outlook.MAPIFolder calendarFolder = mapiNamespace.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderCalendar);
Outlook.Items outlookCalendarItems = calendarFolder.Items;

Outlook.AppointmentItem appointmentItem = (Outlook.AppointmentItem)outlookCalendarItems.Find("[GlobalAppointmentID] = '{0}'", myGlobalAppointmentID));

//update or delete appointmentItem here (which I know how to do)
}

I keep getting 'Condition is not valid' Exception. Apparently Outlook does not allow to search on binary properties (such as GlobalAppointmentID).

I use the same outlookCalendarItems.Find() and calendarFolder.Items.Restrict() without problems in other instances.

I tried using Redemption but I couldn't get it to work either. Does anybody have experience or a suggestion?

Answer 1

What I ended up doing after looking further: I added a text UserProperty where I put the GlobalAppointmentID("GAID") in. You can Filter on those. And it seems to do the trick.

private void AddGAIDIfNeeded(Outlook.AppointmentItem app)
        {
            bool GAIDexists = false;
            if (app.UserProperties.Count != 0)
            {
                foreach (UserProperty item in app.UserProperties)
                {
                    if (item.Name == "GAID")
                    {
                        GAIDexists = true;
                        break;
                    }
                }
            }

            if (GAIDexists == false)
            {
                app.UserProperties.Add("GAID", Outlook.OlUserPropertyType.olText);
                app.UserProperties["GAID"].Value = app.GlobalAppointmentID;
                app.Save();
            }
        }

And to find a specific AppointmentItem:

private void DeleteOutlookAppointmentByGAID(string globalAppointmentID)
        {
            Outlook.Application oApp = new Outlook.Application();
            Outlook.NameSpace mapiNamespace = oApp.GetNamespace("MAPI");
            Outlook.MAPIFolder calendarFolder = mapiNamespace.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderCalendar);
            Outlook.Items outlookCalendarItems = calendarFolder.Items;

            try
            {
                Outlook.AppointmentItem appointmentItem = null;
                appointmentItem = outlookCalendarItems.Find(String.Format("[GAID] = '{0}'", globalAppointmentID));

                if (appointmentItem != null)
                {
                    appointmentItem.Delete();
                }
            }
            catch (Exception ex)
            {
                classExecptionLogging.LogErrorToFolder(ex);
            }

        }