Exchange 2007 Web Services (III): Update a calendar item (UpdateItem)

In my previous post, I explained how create a calendar item with an extended property and how find this calendar item by the extended property.

In this post, I will explain how to update this calendar item, modifying the appointment's End datetime.

This is the commented code:

public void UpdateAppointment(CalendarItemType calendarItem)
{
    try
    {
        // Delegate to accept server certificate
        ServicePointManager.ServerCertificateValidationCallback =
            delegate(Object obj, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
            {
                return true;
            };

        // Init Web Service Instance
        ExchangeServiceBinding ewsService = new ExchangeServiceBinding();

        // Set credentials and URL
        ewsService.Credentials = new NetworkCredential("user", "qwerty", "DOMAIN");
        ewsService.Url = @"https://server.domain.com/ews/exchange.asmx";

        // If we need pass through a proxy
        ewsService.Proxy = new WebProxy("proxy.domain.com", true);
        ewsService.Proxy.Credentials = System.Net.CredentialCache.DefaultCredentials;

        // Exchange properties
        ewsService.RequestServerVersionValue = new RequestServerVersion();
        ewsService.RequestServerVersionValue.Version = ExchangeVersionType.Exchange2007_SP1;

        // Initialize the instance to pass to the web service method
        UpdateItemType updateItem = new UpdateItemType();
        updateItem.ItemChanges = new ItemChangeType[1];
        updateItem.ItemChanges[0] = new ItemChangeType();

        // Set the Calendar Item's ID (the item wich will be updated)
        updateItem.ItemChanges[0].Item = calendarItem.ItemId;
        updateItem.ItemChanges[0].Updates = new ItemChangeDescriptionType[1];

        // The instance to modify the End property
        SetItemFieldType setCalendarEnd = new SetItemFieldType();

        // The path to the End property
        PathToUnindexedFieldType calendarEndPath = new PathToUnindexedFieldType();
        calendarEndPath.FieldURI = UnindexedFieldURIType.calendarEnd;                

        // The new End property's value
        CalendarItemType calendarEndItem = new CalendarItemType();
        calendarEndItem.End = new DateTime(2008, 08, 28, 17, 00, 00);
        // If no -> ErrorIncorrectUpdatePropertyCount
        calendarEndItem.EndSpecified = true;

        setCalendarEnd.Item = calendarEndPath;
        setCalendarEnd.Item1 = calendarEndItem;

        updateItem.ItemChanges[0].Updates[0] = setCalendarEnd;

        // This property is required in the UpdateItem method, when we update calendar items
        updateItem.SendMeetingInvitationsOrCancellations = CalendarItemUpdateOperationType.SendToNone;
        updateItem.SendMeetingInvitationsOrCancellationsSpecified = true;

        // Invoke the web service method
        UpdateItemResponseType response = ewsService.UpdateItem(updateItem);

        // Get the response
        UpdateItemResponseMessageType updateItemResponse =
                    (UpdateItemResponseMessageType)response.ResponseMessages.Items[0];

        // Check the result
        if (updateItemResponse.ResponseClass != ResponseClassType.Success)
        {
            // An error occurs
            Console.Out.WriteLine("[UPDATE ITEM RESULTS]");
            Console.Out.WriteLine(updateItemResponse.ResponseClass);
            Console.Out.WriteLine(updateItemResponse.ResponseCode);
            Console.Out.WriteLine(updateItemResponse.MessageText);
        }
        else
        {
            // No error
            Console.Out.WriteLine("[UPDATE ITEM RESULTS]");
            Console.Out.WriteLine(updateItemResponse.ResponseClass);
            Console.Out.WriteLine(updateItemResponse.ResponseCode);                    
        }                                
    }
    catch (Exception ex)
    {                
        // An unexpected error
        string message = ex.Message;
        Console.Out.WriteLine(string.Format("Unexpected error...{0}", message));
    }
}

Pay attention to this line:

calendarEndItem.End = new DateTime(2008, 08, 28, 17, 00, 00);
calendarEndItem.EndSpecified = true;

If we don't set EndSpecified property, we will receive a confusing error code: ErrorIncorrectUpdatePropertyCount.