我尝试编写一个使用EWS API（2.2）查询Exchange的Web服务。我可以使用Console.Write获取数据，但我想向SOAP Web服务的用户提供数据。
我使用以下代码：
public class GetAppointments
{
public static List<Appointment> GetAppointment()
{
ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2010_SP2);
service.UseDefaultCredentials = true;
//service.Credentials = new WebCredentials("username", "password", "domain");
service.TraceEnabled = true;
service.TraceFlags = TraceFlags.All;
service.AutodiscoverUrl("service@organisation.com", RedirectionUrlValidationCallback);
//service.ImpersonatedUserId = new ImpersonatedUserID(ConnectingIdType.SmtpAddres, "user@domain");
// Initialize values for the start and end times, and the number of appointments to retrieve.
DateTime startDate = DateTime.Now;
DateTime endDate = startDate.AddDays(30);
//const int NUM_APPTS = 5;
// Initialize the calendar folder object with only the folder ID.
CalendarFolder calendar = CalendarFolder.Bind(service, WellKnownFolderName.Calendar, new PropertySet());
// Set the start and end time and number of appointments to retrieve.
// CalendarView cView = new CalendarView(startDate, endDate, NUM_APPTS);
ItemView view = new ItemView(100);
// Set the mailbox to query
String MailBoxToAccess = "myname@organisation.com";
FolderId CalendarFolderId = new FolderId(WellKnownFolderName.Calendar, MailBoxToAccess);
// Limit the properties returned to the appointment's subject, start time, and end time.
view.PropertySet = new PropertySet(AppointmentSchema.Subject, AppointmentSchema.Start, AppointmentSchema.End);
// Retrieve a collection of appointments by using the calendar view.
//FindItemsResults<Appointment> appointments = service.FindAppointments(CalendarFolderId, cView);
SearchFilter subjectFilter = new SearchFilter.IsEqualTo(AppointmentSchema.Subject, "TEST");
FindItemsResults<Item> appointments = service.FindItems(CalendarFolderId, subjectFilter, view);
List<Appointment> AppointmentResult = new List<Appointment>();
if (appointments.Items.Count > 0)
{
foreach (Appointment a in appointments)
{
var ApptResult = new Appointment(service)
{
Subject = a.Subject,
Start = a.Start,
End = a.End,
};
AppointmentResult.Add(ApptResult);
}
}
else
{
return null;
}
return AppointmentResult;
}
private static bool RedirectionUrlValidationCallback(string redirectionUrl)
{
// The default for the validation callback is to reject the URL.
bool result = false;
Uri redirectionUri = new Uri(redirectionUrl);
// Validate the contents of the redirection URL. In this simple validation
// callback, the redirection URL is considered valid if it is using HTTPS
// to encrypt the authentication credentials.
if (redirectionUri.Scheme == "https")
{
result = true;
}
return result;
}
}
当我尝试运行它时出现以下错误：
* Microsoft.Exchange.WebServices.Data.Appointment无法序列化，因为它没有无参数构造函数。
描述：执行当前Web请求期间发生了未处理的异常。请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息。
异常详细信息：System.InvalidOperationException：无法序列化Microsoft.Exchange.WebServices.Data.Appointment，因为它没有无参数构造函数。
来源错误： 在执行当前Web请求期间生成了未处理的异常。可以使用下面的异常堆栈跟踪来识别有关异常的起源和位置的信息。
Stack Trace:
[InvalidOperationException: Microsoft.Exchange.WebServices.Data.Appointment cannot be serialized because it does not have a parameterless constructor.]
System.Xml.Serialization.TypeDesc.CheckSupported() +5651485
System.Xml.Serialization.TypeDesc.CheckSupported() +45
System.Xml.Serialization.TypeScope.GetTypeDesc(Type type, MemberInfo source, Boolean directReference, Boolean throwOnError) +172
System.Xml.Serialization.XmlReflectionImporter.ImportMemberMapping(XmlReflectionMember xmlReflectionMember, String ns, XmlReflectionMember[] xmlReflectionMembers, Boolean rpc, Boolean openModel, RecursionLimiter limiter) +73
System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping(XmlReflectionMember[] xmlReflectionMembers, String ns, Boolean hasWrapperElement, Boolean rpc, Boolean openModel, RecursionLimiter limiter) +286
[InvalidOperationException: There was an error reflecting 'GetAppointmentResult'.]
System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping(XmlReflectionMember[] xmlReflectionMembers, String ns, Boolean hasWrapperElement, Boolean rpc, Boolean openModel, RecursionLimiter limiter) +899
System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping(String elementName, String ns, XmlReflectionMember[] members, Boolean hasWrapperElement, Boolean rpc, Boolean openModel, XmlMappingAccess access) +133
System.Web.Services.Protocols.SoapReflector.ImportMembersMapping(XmlReflectionImporter xmlImporter, SoapReflectionImporter soapImporter, Boolean serviceDefaultIsEncoded, Boolean rpc, SoapBindingUse use, SoapParameterStyle paramStyle, String elementName, String elementNamespace, Boolean nsIsDefault, XmlReflectionMember[] members, Boolean validate, Boolean openModel, String key, Boolean writeAccess) +233
System.Web.Services.Protocols.SoapReflector.ReflectMethod(LogicalMethodInfo methodInfo, Boolean client, XmlReflectionImporter xmlImporter, SoapReflectionImporter soapImporter, String defaultNs) +2862
[InvalidOperationException: Method WebService.GetAppointment can not be reflected.]
System.Web.Services.Protocols.SoapReflector.ReflectMethod(LogicalMethodInfo methodInfo, Boolean client, XmlReflectionImporter xmlImporter, SoapReflectionImporter soapImporter, String defaultNs) +6262
System.Web.Services.Description.SoapProtocolReflector.ReflectMethod() +137
System.Web.Services.Description.ProtocolReflector.ReflectBinding(ReflectedBinding reflectedBinding) +1577
System.Web.Services.Description.ProtocolReflector.Reflect() +641
System.Web.Services.Description.ServiceDescriptionReflector.ReflectInternal(ProtocolReflector[] reflectors) +559
System.Web.Services.Description.ServiceDescriptionReflector.Reflect(Type type, String url) +109
System.Web.Services.Protocols.DocumentationServerType..ctor(Type type, String uri, Boolean excludeSchemeHostPortFromCachingKey) +230
System.Web.Services.Protocols.DocumentationServerProtocol.Initialize() +472
System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type, HttpContext context, HttpRequest request, HttpResponse response, Boolean& abortProcessing) +122
[InvalidOperationException: Unable to handle request.]
System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type, HttpContext context, HttpRequest request, HttpResponse response, Boolean& abortProcessing) +325
System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler(Type type, HttpContext context, HttpRequest request, HttpResponse response) +171
[InvalidOperationException: Failed to handle request.]
System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler(Type type, HttpContext context, HttpRequest request, HttpResponse response) +346
System.Web.Services.Protocols.WebServiceHandlerFactory.GetHandler(HttpContext context, String verb, String url, String filePath) +209
System.Web.Script.Services.ScriptHandlerFactory.GetHandler(HttpContext context, String requestType, String url, String pathTranslated) +47
System.Web.HttpApplication.MapHttpHandler(HttpContext context, String requestType, VirtualPath path, String pathTranslated, Boolean useAppConfig) +226
System.Web.MapHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +145
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155*
我不确定我需要做些什么来克服这个问题，或者我是否正确地解决了这个问题。我愿意接受建议。
答案 0 :(得分：4)
通过API发送第三方对象并不总是一个好主意，在这种情况下，它肯定是这样的。您需要考虑API的使用者需要在另一端重建类，如果它没有无参数构造函数，则不可能。
相反，最好创建自己的模型并从中发送所需的值。例如，假设Appointment类看起来像这样（我知道它没有，但它作为一个例子）：
public class Appointment
{
public string Title { get; set; }
public string Body { get; set; }
public DateTime MeetingTime { get; set; }
}
然后创建自己的类，模仿Appointment：
public class AppointmentModel
{
public string Title { get; set; }
public string Body { get; set; }
public DateTime MeetingTime { get; set; }
}
现在不返回Appointment，而是返回自己的模型：
public static List<Appointment> GetAppointment()
{
//snip
List<Appointment> appointments = GetAllAppointments()
//Use some Linq to project into your own model
return appointments
.Select(a => new AppointmentModel
{
Title = a.Title,
Body = a.Body,
MeetingTime = a.MeetingTime
})
.ToList();
}