Exchange 2007 Web Services (II): Find a calendar item by an Extended Property (FindItem)

In my previous post, I explained how to create a calendar item in Exchange 2007 through Exchange Web Services (EWS) with an extended property (NetShowUrl).

In this post, I will show you, how to find this calendar item by this property.

Here is the commented code:

public CalendarItemType FindAppointment(String filterValue)
{
    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;
                
            // Set Exchange properties 
            ewsService.RequestServerVersionValue = new RequestServerVersion();
            ewsService.RequestServerVersionValue.Version = ExchangeVersionType.Exchange2007_SP1;

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

            // Set the Calendary folder to save the item       
            DistinguishedFolderIdType[] folders = new DistinguishedFolderIdType[1];
            folders[0] = new DistinguishedFolderIdType();
            folders[0].Id = DistinguishedFolderIdNameType.calendar;
            // If we need to find the another's user item 
            //folders[0].Mailbox = new EmailAddressType();
            //folders[0].Mailbox.EmailAddress = "user1@example.com";                
            item.ParentFolderIds = folders;

            // Extended Property by we do the search                
            PathToExtendedFieldType netShowUrlPath = new PathToExtendedFieldType();
            Guid mapiGuid = new Guid("{00062002-0000-0000-C000-000000000046}");
            netShowUrlPath.PropertySetId = mapiGuid.ToString ("D");
            netShowUrlPath.PropertyId = 0x8248; // NetShowUrl
            netShowUrlPath.PropertyIdSpecified = true;
            netShowUrlPath.PropertyType = MapiPropertyTypeType.String;

            // To get this extra property to in our search
            PathToUnindexedFieldType datetimestampPath = new PathToUnindexedFieldType();
            datetimestampPath.FieldURI = UnindexedFieldURIType.calendarDateTimeStamp;
                
            // We set wich properties we want
            item.ItemShape = new ItemResponseShapeType();
            item.ItemShape.BaseShape = DefaultShapeNamesType.AllProperties;
            item.ItemShape.AdditionalProperties = new BasePathToElementType[2];
            item.ItemShape.AdditionalProperties[0] = netShowUrlPath;
            item.ItemShape.AdditionalProperties[1] = datetimestampPath;

            // The Filter               
            item.Restriction = new RestrictionType();                
            IsEqualToType filterNetShowUrl = new IsEqualToType();
            filterNetShowUrl.FieldURIOrConstant = new FieldURIOrConstantType();
            FieldURIOrConstantType netShowUrlConstanType = new FieldURIOrConstantType();
            ConstantValueType netShowUrlConstantValueType = new ConstantValueType();
            netShowUrlConstantValueType.Value = filterValue;
            netShowUrlConstanType.Item = netShowUrlConstantValueType;
            filterNetShowUrl.Item = netShowUrlPath;
            filterNetShowUrl.FieldURIOrConstant = netShowUrlConstanType;                                
            item.Restriction.Item = filterNetShowUrl;

            // Invoke the web service method
            FindItemResponseType response = ewsService.FindItem (item);

            // Get the response
            FindItemResponseMessageType findItemResponse =
            (FindItemResponseMessageType)response.ResponseMessages.Items[0];

            // Check the result
            if (findItemResponse.ResponseClass != ResponseClassType.Success)
            {
               // An error occurs
               Console.Out.WriteLine("[FIND ITEM RESULTS]");
               Console.Out.WriteLine(findItemResponse.ResponseClass);
               Console.Out.WriteLine(findItemResponse.ResponseCode);
               Console.Out.WriteLine(findItemResponse.MessageText);

               return null;
             }
             else
             {
               // Get the first item
               ArrayOfRealItemsType arrayItems = (ArrayOfRealItemsType)findItemResponse.RootFolder.Item;
               CalendarItemType appointmentItem = (CalendarItemType)arrayItems.Items[0];

               // Print the item's info
               Console.Out.WriteLine("[FIND ITEM RESULTS]");
               Console.Out.WriteLine(appointmentItem.Start);
               Console.Out.WriteLine(appointmentItem.End);
               Console.Out.WriteLine(appointmentItem.Subject);
               Console.Out.WriteLine(appointmentItem.Location);
               Console.Out.WriteLine(appointmentItem.DateTimeStamp.ToUniversalTime().ToString());

               // Return the Item
               return appointmentItem;
             }
     }
     catch (Exception ex)
     {
        // An unexpected error
        string message = ex.Message;
        Console.Out.WriteLine(string.Format("Unexpected error...{0}", message));
        return null;
      }
}