Exchange 2007 Web Services (I): Create a calendar item with an Extended Property (CreateItem)

Here is my code sample to create an appointment item in Exchange 2007 throug Exchange Web Services (EWS), using the CreateItem method. It's commented, I hope that is sufficient to explain how to use this Exchange 2007 feature.

Also, in this sample, I explain how to add an Extended Property to our calendar item (in next post, I'll show you how to find this calendar item through this Extended Property):

public void CreateAppointment(DateTime fecha)
{
     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;
                
       // Create the appointment instance
       CalendarItemType appointmentItem = new CalendarItemType();              

       // Set Start and End Properties 
       appointmentItem.Start = DateTime.Now.AddHours(-1);
       appointmentItem.End = DateTime.Now.AddHours(1);

       // Set Location
       appointmentItem.Location = "Meeting point";

       // Set the Subject
       appointmentItem.Subject = "Talk about Exchange 2007";
                
       // Set the Appointment's Body
       appointmentItem.Body = new BodyType();
       appointmentItem.Body.BodyType1 = BodyTypeType.Text;
       appointmentItem.Body.Value = "Esto es una cita de prueba.";

       // According to previous Exchange's versions
       appointmentItem.ItemClass = "IPM.Appointment";                                               

       // We set an extra property
       appointmentItem.DateTimeStamp = fecha;

       // We set an Extended Property (NetShowUrl)
       appointmentItem.ExtendedProperty = new ExtendedPropertyType[1];
       appointmentItem.ExtendedProperty[0] = new ExtendedPropertyType();
       PathToExtendedFieldType pathNetShowUrl = new PathToExtendedFieldType();
       Guid mapiGuid = new Guid("{00062002-0000-0000-C000-000000000046}");
       pathNetShowUrl.PropertySetId = mapiGuid.ToString ("D");
       pathNetShowUrl.PropertyId = 0x8248; 
       pathNetShowUrl.PropertyIdSpecified = true;
       pathNetShowUrl.PropertyType = MapiPropertyTypeType.String;
       appointmentItem.ExtendedProperty[0].ExtendedFieldURI = pathNetShowUrl;
       appointmentItem.ExtendedProperty[0].Item = "My NetShowUrl Property value";

       // Initialize the instance to pass to the web service method
       CreateItemType item = new CreateItemType();

       // We add our appointment item to the parameters
       item.Items = new NonEmptyArrayOfAllItemsType();
       item.Items.Items = new ItemType[1];
       item.Items.Items[0] = appointmentItem;

       // Set the Calendary folder to save the item
       DistinguishedFolderIdType calendarFolder = new DistinguishedFolderIdType();
       calendarFolder.Id = DistinguishedFolderIdNameType.calendar;
       calendarFolder.Mailbox = new EmailAddressType();                               
       item.SavedItemFolderId = new TargetFolderIdType();
       item.SavedItemFolderId.Item = calendarFolder;
                
       // Set if we need to send to appointment's people and invitation
       //  (Required Property in CalendarItem)
       item.SendMeetingInvitations = CalendarItemCreateOrDeleteOperationType.SendToNone;
       item.SendMeetingInvitationsSpecified = true;                

       // Invoke the web service method
       CreateItemResponseType response = ewsService.CreateItem(item);                                

       // Get the response
       ItemInfoResponseMessageType itemInfoResponse =
          (ItemInfoResponseMessageType)response.ResponseMessages.Items[0];

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