Search EWS CalendarItems with last modified time

I'm searching for CalendarItems with Exchange Web Services. In the documenta开发者_如何转开发tion on MSDN there is a field named LastModifiedTime.

How do I query CalendarItems by LastModifiedTime with Exchange Server Bindings?

I found out a way with using restictions

(but by searching If findItemRequest object's findItemRequest.Item findItemRequest.Restictions properties are defined It gives combination error...)

If only Item or Restictions is defined for findItemRequest object it works

        List<CalendarInfo> calendarEvents = new List<CalendarInfo>();

        ExchangeServiceBinding esb = EWS.Helper.ExchangeHelper.GetExchangeBinding(credentials);

        // Form the FindItem request.
        FindItemType findItemRequest = new FindItemType();


        CalendarViewType calendarView = new CalendarViewType();
        calendarView.StartDate = criteria.StartDateAndTime;
        calendarView.EndDate = criteria.EndDateAndTime;

        if (criteria.MaxItemsToReturn > 0)
        {
            calendarView.MaxEntriesReturned = criteria.MaxItemsToReturn;
            calendarView.MaxEntriesReturnedSpecified = true;
        }

        findItemRequest.Item = calendarView;

        //--
        PathToExtendedFieldType sySyncProp = new PathToExtendedFieldType();



        sySyncProp.PropertyTag = "0x3008";
        sySyncProp.PropertyType = MapiPropertyTypeType.SystemTime;
        // Define restrictions

        RestrictionType ffRestriction = new RestrictionType();
        IsGreaterThanOrEqualToType ieGreater = new IsGreaterThanOrEqualToType();

        ieGreater.FieldURIOrConstant =  new FieldURIOrConstantType();
        ieGreater.FieldURIOrConstant.Item = new ConstantValueType();
        (ieGreater.FieldURIOrConstant.Item as ConstantValueType).Value = DateTime.Now.AddDays(-1).ToUniversalTime().ToString("u");
        ieGreater.Item = sySyncProp;

        ffRestriction.Item = ieGreater;

       findItemRequest.Restriction = ffRestriction;

        //--
        // Define which item properties are returned in the response.
        ItemResponseShapeType itemProperties = new ItemResponseShapeType();

        // Use the Default shape for the response. 
        itemProperties.BaseShape = DefaultShapeNamesType.AllProperties;
        //insert last modified time value also to responses
        PathToExtendedFieldType[] ptufta = new PathToExtendedFieldType[1];
        ptufta[0] = new PathToExtendedFieldType();
        ptufta[0].PropertyTag = "0x3008"; //Property Tag for LastModifiedTime 
        ptufta[0].PropertyType = MapiPropertyTypeType.SystemTime;
        itemProperties.AdditionalProperties = ptufta;

        findItemRequest.ItemShape = itemProperties;

        DistinguishedFolderIdType[] folderIDArray = new DistinguishedFolderIdType[1];
        folderIDArray[0] = new DistinguishedFolderIdType();
        folderIDArray[0].Id = DistinguishedFolderIdNameType.calendar;

        if (!string.IsNullOrEmpty(criteria.EmailAddress))
        {
            folderIDArray[0].Mailbox = new EmailAddressType();
            folderIDArray[0].Mailbox.EmailAddress = criteria.EmailAddress.Trim();
        }

        findItemRequest.ParentFolderIds = folderIDArray;

        // Define the traversal type.
        findItemRequest.Traversal = ItemQueryTraversalType.Shallow;

        try
        {
            // Send the FindItem request and get the response.
            FindItemResponseType findItemResponse = esb.FindItem(findItemRequest);

            // Access the response message.
            ArrayOfResponseMessagesType responseMessages = findItemResponse.ResponseMessages;
            ResponseMessageType[] rmta = responseMessages.Items;

            int folderNumber = 0;

            foreach (ResponseMessageType rmt in rmta)
            {
                // One FindItemResponseMessageType per folder searched.
                FindItemResponseMessageType firmt = rmt as FindItemResponseMessageType;

                if (firmt.RootFolder == null)
                    continue;

                FindItemParentType fipt = firmt.RootFolder;
                object obj = fipt.Item;

                // FindItem contains an array of items.
                if (obj is ArrayOfRealItemsType)
                {
                    ArrayOfRealItemsType items = (obj as ArrayOfRealItemsType);
                    if (items.Items == null)
                    {
                        // Console.WriteLine("Folder {0}: No items in folder", folderNumber);
                        folderNumber++;
                    }
                    else
                    {
                        CalendarInfo ce;
                        CalendarItemType cal;
                        foreach (ItemType it in items.Items)
                        {

                            if (it is CalendarItemType)
                            {
                                cal = (CalendarItemType)it;
                                ce = GetCalendarInfo(esb, cal);
                                calendarEvents.Add(ce);
                            }
                            //Console.WriteLine("Folder {0}: Item identifier: {1}", folderNumber, it.ItemId.Id);

                        }

                        folderNumber++;
                    }
                }
            }

            //Console.ReadLine();
        }
        catch (Exception e)
        {
            throw;
        }


        return calendarEvents;