c# - EWS - 尝试加载与会者时列出日历约会失败

Question

我正在尝试使用 C# EWS 2.0 库列出一些事件。

它使用以下代码:

    public IEnumerable<AppEvent> ListEvents(CalendarFolder folder, DateTime? startDate, DateTime? endDate)
    {
        var items = new List<AppEvent>();

        var now = DateTime.Now;
        if (startDate == null) startDate = DateTime.Now;
        if (endDate == null) endDate = now.AddDays(14);

        FindItemsResults<Appointment> findResults = null;
        ServiceResponseCollection<GetItemResponse> appointments = null;
        CalendarView view = null;

        view = new CalendarView((DateTime)startDate, (DateTime)endDate);
        findResults = folder.FindAppointments(view);

        if (findResults.Items.Count() == 0) return items;
        appointments = Service.BindToItems(findResults.Select(item => item.Id), AppointmentPropertySet);

        foreach (GetItemResponse item in appointments)
        {
            var appointment = item.Item as Appointment;
            try
            {
                if (appointment.IsCancelled) continue;
            }
            catch (System.NullReferenceException)
            {
                continue;
            }
            var evt = AppEvent.FromEWSAppointment(appointment);
            items.Add(evt);
        }

        return items;
    }

而AppointmentPropertySet如下:

    protected PropertySet AppointmentPropertySet = new PropertySet(
        AppointmentSchema.Subject, 
        AppointmentSchema.Start,
        AppointmentSchema.End, 
        AppointmentSchema.IsAllDayEvent, 
        AppointmentSchema.IsMeeting,
        AppointmentSchema.IsRecurring, 
        AppointmentSchema.IsCancelled,
        AppointmentSchema.IsDraft, 
        AppointmentSchema.Location,
        AppointmentSchema.Resources,
        AppointmentSchema.RequiredAttendees, 
        AppointmentSchema.OptionalAttendees,
        AppointmentSchema.LegacyFreeBusyStatus,
        AppointmentSchema.Organizer, 
        AppointmentSchema.Body,
        AppointmentSchema.Sensitivity,
        AppointmentSchema.AppointmentReplyTime,
        AppointmentSchema.AppointmentSequenceNumber,
        AppointmentSchema.AppointmentState,
        AppointmentSchema.AppointmentType,
        AppointmentSchema.ConferenceType,
        AppointmentSchema.DateTimeCreated,
        AppointmentSchema.Duration,
        AppointmentSchema.EndTimeZone,
        AppointmentSchema.HasAttachments,
        AppointmentSchema.ICalDateTimeStamp,
        AppointmentSchema.ICalRecurrenceId,
        AppointmentSchema.ICalUid,
        AppointmentSchema.Id,
        AppointmentSchema.Importance,
        AppointmentSchema.IsOnlineMeeting,
        AppointmentSchema.IsReminderSet,
        AppointmentSchema.IsResponseRequested,
        AppointmentSchema.IsUnmodified,
        AppointmentSchema.LastModifiedTime,
        AppointmentSchema.LegacyFreeBusyStatus,
        AppointmentSchema.MeetingRequestWasSent,
        AppointmentSchema.MyResponseType,
        AppointmentSchema.MeetingWorkspaceUrl,
        AppointmentSchema.NetShowUrl,
        AppointmentSchema.OriginalStart,
        AppointmentSchema.ParentFolderId,
        AppointmentSchema.Recurrence,
        AppointmentSchema.ReminderDueBy,
        AppointmentSchema.ReminderMinutesBeforeStart,
        AppointmentSchema.StartTimeZone,
        AppointmentSchema.WebClientEditFormQueryString,
        AppointmentSchema.WebClientReadFormQueryString
        );

其中一个事件出现以下错误。如果我从 AppointmentPropertySet 中删除 RequiredAttendees 和 OptionalAttendees，它工作正常(尽管没有返回任何与会者)。

如何避免此错误，或者如何跳过此事件以便 View 至少返回未中断的约会？

System.ArgumentException: Requested value 'User' was not found.
   at System.Enum.EnumResult.SetFailure(ParseFailureKind failure, String failureMessageID, Object failureMessageFormatArgument)
   at System.Enum.TryParseEnum(Type enumType, String value, Boolean ignoreCase, EnumResult& parseResult)
   at System.Enum.Parse(Type enumType, String value, Boolean ignoreCase)
   at Microsoft.Exchange.WebServices.Data.EwsUtilities.Parse[T](String value)
   at Microsoft.Exchange.WebServices.Data.EwsXmlReader.ReadElementValue[T]()
   at Microsoft.Exchange.WebServices.Data.EmailAddress.TryReadElementFromXml(EwsServiceXmlReader reader)
   at Microsoft.Exchange.WebServices.Data.Attendee.TryReadElementFromXml(EwsServiceXmlReader reader)
   at Microsoft.Exchange.WebServices.Data.ComplexProperty.InternalLoadFromXml(EwsServiceXmlReader reader, XmlNamespace xmlNamespace, String xmlElementName, Func`2 readAction)
   at Microsoft.Exchange.WebServices.Data.ComplexProperty.LoadFromXml(EwsServiceXmlReader reader, XmlNamespace xmlNamespace, String xmlElementName)
   at Microsoft.Exchange.WebServices.Data.Attendee.TryReadElementFromXml(EwsServiceXmlReader reader)
   at Microsoft.Exchange.WebServices.Data.ComplexProperty.InternalLoadFromXml(EwsServiceXmlReader reader, XmlNamespace xmlNamespace, String xmlElementName, Func`2 readAction)
   at Microsoft.Exchange.WebServices.Data.ComplexProperty.LoadFromXml(EwsServiceXmlReader reader, XmlNamespace xmlNamespace, String xmlElementName)
   at Microsoft.Exchange.WebServices.Data.ComplexPropertyCollection`1.LoadFromXml(EwsServiceXmlReader reader, XmlNamespace xmlNamespace, String localElementName)
   at Microsoft.Exchange.WebServices.Data.ComplexPropertyDefinitionBase.InternalLoadFromXml(EwsServiceXmlReader reader, PropertyBag propertyBag)
   at Microsoft.Exchange.WebServices.Data.ComplexPropertyDefinitionBase.LoadPropertyValueFromXml(EwsServiceXmlReader reader, PropertyBag propertyBag)
   at Microsoft.Exchange.WebServices.Data.PropertyBag.LoadFromXml(EwsServiceXmlReader reader, Boolean clear, PropertySet requestedPropertySet, Boolean onlySummaryPropertiesRequested)
   at Microsoft.Exchange.WebServices.Data.EwsServiceXmlReader.ReadServiceObjectsCollectionFromXml[TServiceObject](XmlNamespace collectionXmlNamespace, String collectionXmlElementName, GetObjectInstanceDelegate`1 getObjectInstanceDelegate, Boolean clearPropertyBag, PropertySet requestedPropertySet, Boolean summaryPropertiesOnly)
   at Microsoft.Exchange.WebServices.Data.GetItemResponse.ReadElementsFromXml(EwsServiceXmlReader reader)
   at Microsoft.Exchange.WebServices.Data.ServiceResponse.LoadFromXml(EwsServiceXmlReader reader, String xmlElementName)
   at Microsoft.Exchange.WebServices.Data.MultiResponseServiceRequest`1.ParseResponse(EwsServiceXmlReader reader)
   at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ReadResponse(EwsServiceXmlReader ewsXmlReader)
   at Microsoft.Exchange.WebServices.Data.SimpleServiceRequestBase.ReadResponseXml(Stream responseStream)
   at Microsoft.Exchange.WebServices.Data.SimpleServiceRequestBase.ReadResponse(IEwsHttpWebResponse response)
   at Microsoft.Exchange.WebServices.Data.ExchangeService.InternalBindToItems(IEnumerable`1 itemIds, PropertySet propertySet, ServiceErrorHandling errorHandling)
   at ExchangeAppService.Utilities.API.ExchangeAPI.ListEvents(CalendarFolder folder, Nullable`1 startDate, Nullable`1 endDate) in c:\Users\Some Guy\Documents\Visual Studio 2013\Projects\ExchangeAppService\ExchangeAppService\Utilities\API\Exchange\ExchangeAPI.cs:line 195

Answer 1

根据异常堆栈跟踪判断，我很确定您的交换服务器正在为一个(或多个)与会者电子邮件地址的 MailboxType 回复一个无效值(“用户”)。

查看 current implementation of the MailboxType enum即使是最新版本，“用户”值似乎也是无效的。

您应该能够通过分析 Exchange 返回给您的 soap 响应、跟踪它(参见 How to: Trace requests and responses to troubleshoot EWS Managed API applications )或使用像 Fiddler 或 Wireshark 这样的网络分析器来进一步确认这一点。

如果是这种情况，我认为唯一的解决办法是在他们的 github repo 上提出问题，并希望他们能为您提供更多信息或可能的解决方案。