C# EWS-尝试加载与会者时列表日历约会失败

我试图使用C#EWS 2.0库列出一些事件

它正在使用以下代码：

    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;
    }

我们得到其中一个事件的以下错误。如果我从

AppointmentPropertySet

中删除

RequiredAttendes

和

OptionalAttendes

，它可以正常工作（尽管不会返回任何与会者）

如何避免此错误，或者如何跳过此事件，以便视图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

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根据异常堆栈跟踪判断，我非常确定您的exchange服务器正在使用一个（或多个）与会者电子邮件地址的MailboxType的无效值（“用户”）进行回复

从最新版本来看，“User”值似乎是无效的

您应该能够通过分析Exchange返回给您的soap响应、跟踪它（请参阅）或使用Fiddler或Wireshark等网络分析器来进一步确认这一点

---

如果是这样的话，我认为唯一的解决办法是在他们的网站上发布一个问题，希望他们能为您提供更多信息或您的问题的可能解决方案。

2017/12/15在github发布了一个问题

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还没有回应。我们已经开始在大约30%的a客户邮箱中遇到同样的问题，我们担心这会蔓延

您是否仍然存在此问题？如果您已经修复了它，请将您的解决方案作为答案发布，它可能对遇到相同问题的其他人有用。我仍然拥有它。您尝试过我的答案吗？它不起作用？是的，我有我认为是最新的EWS托管API，但是，在nuget中，有几个选项，我不确定哪一个是最好的。我还将注意到，并非每次约会都会出现这种情况。只是其中的一部分。看来我要和他们一起打开一个漏洞了。谢谢你抽出时间！没问题，我希望我不会很快遇到和你一样的问题：）另外，如果你在他们的回购协议上打开了一个问题，请回来分享它的链接和/或结果，这样将来的人（包括我）可以找到解决方案或至少跟踪问题的状态。

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