无法序列成员＆LT; X＆GT;因为它是一个接口 [英] Cannot serialize member <x> because it is an interface

问题描述

请按照从<一个问题href=\"http://stackoverflow.com/questions/31563378/error-with-explicit-conversion-when-using-collectas/31566114#31566114\">Error用显式转换时使用CollectAs＆LT;＆GT;

从的WebMethod code

Code from WebMethod

return client.Cypher
        .Match("(person:Person)")
        .Where((Person person) => person.Email == username)
        .OptionalMatch("(person)-[:SPEAKS]-(language:Language)")
        .OptionalMatch("(person)-[:CURRENT_LOCATION]-(country:Country)"
        .Return((person, language, country) => new ProfileObject
        {
            Person = person.As<Person>(),
            Language = language.CollectAs<Language>(),
            Country = country.CollectAs<Country>()
        }).Results.ToList();

从国家类code：

Code from Country Class:

public class Language
{
    public string Name { get; set; }
}

从ProfileObject类新的code：

New code from ProfileObject Class:

public class ProfileObject
{
    public Person Person { get; set; }
    public IEnumerable<Node<Language>> Language { get; set; }
    public IEnumerable<Node<Country>> Country { get; set; }
}

此错误只有当我设置ProfileObject返回的IEnumerable>，如果我回到它发生在刚

This error only happens when I set ProfileObject to return IEnumerable>, if I return it to just

public Country Country {get; set;} 

然后它工作（但我明显地得到重复条目的人，每个国家对象返回。

then it works (but I obviously get duplicated Person entries for each Country object returned.

任何人能告诉我解决这个问题，不涉及我翻录所有code出来并重新开始？

Anyone able to show me a solution to this problem that doesn't involve me ripping all of the code out and starting again?

编辑，包括堆栈跟踪：

[出现InvalidOperationException：Neo4jClient.Node`1 [Graph.Language]不能序列化，因为它没有参数的构造函数]

[InvalidOperationException: Neo4jClient.Node`1[Graph.Language] cannot be serialized because it does not have a parameterless constructor.]

[出现InvalidOperationException：无法序列成员Graph.ProfileObject.Language类型System.Collections.Generic.List 1 [Neo4jClient.Node 1 [图表。语言，图形，版本= 1.0.0.0，文化=中立，公钥=空]，Neo4jClient，版本= 0.0.0.0，文化=中立，公钥=空]，请参见内部异常的更多细节。]
   System.Xml.Serialization.StructModel.CheckSupportedMember（TYPEDESC TYPEDESC，成员的MemberInfo，型型）5451673
   System.Xml.Serialization.StructModel.CheckSupportedMember（TYPEDESC TYPEDESC，成员的MemberInfo，型型）+69
   System.Xml.Serialization.StructModel.GetPropertyModel（的PropertyInfo的PropertyInfo）+125
   System.Xml.Serialization.StructModel.GetFieldModel（的MemberInfo的MemberInfo）+89
   System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers（StructMapping映射，StructModel模型，布尔openModel，字符串的typeName，RecursionLimiter限制器）618
   System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping（StructModel模型，NS字符串，布尔openModel，XMLATTRIBUTES一，RecursionLimiter限制器）+378
   System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping（TypeModel模型，NS字符串，ImportContext背景下，string数据类型，XMLATTRIBUTES一，布尔重复，布尔openModel，RecursionLimiter限制器）1799

[InvalidOperationException: Cannot serialize member 'Graph.ProfileObject.Language' of type 'System.Collections.Generic.List1[[Neo4jClient.Node1[[Graph.Language, Graph, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], Neo4jClient, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null]]', see inner exception for more details.] System.Xml.Serialization.StructModel.CheckSupportedMember(TypeDesc typeDesc, MemberInfo member, Type type) +5451673 System.Xml.Serialization.StructModel.CheckSupportedMember(TypeDesc typeDesc, MemberInfo member, Type type) +69 System.Xml.Serialization.StructModel.GetPropertyModel(PropertyInfo propertyInfo) +125 System.Xml.Serialization.StructModel.GetFieldModel(MemberInfo memberInfo) +89 System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter) +618 System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping(StructModel model, String ns, Boolean openModel, XmlAttributes a, RecursionLimiter limiter) +378 System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter) +1799

[InvalidOperationException异常：有反映类型'Graph.ProfileObject'错误]
   System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping（TypeModel模型，NS字符串，ImportContext背景下，string数据类型，XMLATTRIBUTES一，布尔重复，布尔openModel，RecursionLimiter限制器）1917
   System.Xml.Serialization.XmlReflectionImporter.CreateArrayElementsFromAttributes（ArrayMapping arrayMapping，XmlArrayItemAttributes属性，类型arrayElementType，字符串arrayElementNs，RecursionLimiter限制器）+263
   System.Xml.Serialization.XmlReflectionImporter.ImportArrayLikeMapping（ArrayModel模型，NS字符串，RecursionLimiter限制器）+264
   System.Xml.Serialization.XmlReflectionImporter.ImportAccessorMapping（MemberMapping访问，FieldModel模型，XMLATTRIBUTES一，字符串NS，类型choiceIdentifierType，布尔RPC，布尔openModel，RecursionLimiter限制器）5456308
   System.Xml.Serialization.XmlReflectionImporter.ImportMemberMapping（XmlReflectionMember xmlReflectionMember，字符串NS，XmlReflectionMember [] xmlReflectionMembers，布尔RPC，布尔openModel，RecursionLimiter限制器）+852
   System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping（XmlReflectionMember [] xmlReflectionMembers，字符串NS，布尔hasWrapperElement，布尔RPC，布尔openModel，RecursionLimiter限制器）286

[InvalidOperationException: There was an error reflecting type 'Graph.ProfileObject'.] System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter) +1917 System.Xml.Serialization.XmlReflectionImporter.CreateArrayElementsFromAttributes(ArrayMapping arrayMapping, XmlArrayItemAttributes attributes, Type arrayElementType, String arrayElementNs, RecursionLimiter limiter) +263 System.Xml.Serialization.XmlReflectionImporter.ImportArrayLikeMapping(ArrayModel model, String ns, RecursionLimiter limiter) +264 System.Xml.Serialization.XmlReflectionImporter.ImportAccessorMapping(MemberMapping accessor, FieldModel model, XmlAttributes a, String ns, Type choiceIdentifierType, Boolean rpc, Boolean openModel, RecursionLimiter limiter) +5456308 System.Xml.Serialization.XmlReflectionImporter.ImportMemberMapping(XmlReflectionMember xmlReflectionMember, String ns, XmlReflectionMember[] xmlReflectionMembers, Boolean rpc, Boolean openModel, RecursionLimiter limiter) +852 System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping(XmlReflectionMember[] xmlReflectionMembers, String ns, Boolean hasWrapperElement, Boolean rpc, Boolean openModel, RecursionLimiter limiter) +286

[InvalidOperationException异常：有反映MyResult错误]
   System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping（XmlReflectionMember [] xmlReflectionMembers，字符串NS，布尔hasWrapperElement，布尔RPC，布尔openModel，RecursionLimiter限制器）979
   System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping（字符串的ElementName，字符串NS，XmlReflectionMember []的成员，布尔hasWrapperElement，布尔RPC，布尔openModel，XmlMappingAccess访问）+133
   System.Web.Services.Protocols.Soa preflector.ImportMembersMapping（XmlReflectionImporter xmlImporter，健胃preflectionImporter soapImporter，布尔serviceDefaultIsEn codeD，布尔RPC，SoapBindingUse使用，SoapParameterStyle paramStyle，字符串的ElementName，字符串elementNamespace，布尔nsIsDefault ，XmlReflectionMember []的成员，布尔验证，布尔openModel，串键，布尔WRITEACCESS）+240
   System.Web.Services.Protocols.Soa preflector.ReflectMethod（LogicalMethodInfo的MethodInfo，布尔客户端，XmlReflectionImporter xmlImporter，健胃preflectionImporter soapImporter，字符串defaultNs）2893

[InvalidOperationException: There was an error reflecting 'MyResult'.] System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping(XmlReflectionMember[] xmlReflectionMembers, String ns, Boolean hasWrapperElement, Boolean rpc, Boolean openModel, RecursionLimiter limiter) +979 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) +240 System.Web.Services.Protocols.SoapReflector.ReflectMethod(LogicalMethodInfo methodInfo, Boolean client, XmlReflectionImporter xmlImporter, SoapReflectionImporter soapImporter, String defaultNs) +2893

[出现InvalidOperationException：方法ProfileServices.My无法体现]
   System.Web.Services.Protocols.Soa preflector.ReflectMethod（LogicalMethodInfo的MethodInfo，布尔客户端，XmlReflectionImporter xmlImporter，健胃preflectionImporter soapImporter，字符串defaultNs）6173
   System.Web.Services.Description.SoapProtocolReflector.ReflectMethod（）+137
   System.Web.Services.Description.ProtocolReflector.ReflectBinding（ReflectedBinding reflectedBinding）1776
   System.Web.Services.Description.ProtocolReflector.Reflect（）641
   System.Web.Services.Description.ServiceDescriptionReflector.ReflectInternal（ProtocolReflector []反射器）+685
   System.Web.Services.Description.ServiceDescriptionReflector.Reflect（类型类型，字符串URL）+118
   System.Web.Services.Protocols.DocumentationServerType..ctor（类型类型，字符串的uri，布尔excludeSchemeHostPortFromCachingKey）+230
   System.Web.Services.Protocols.DocumentationServerProtocol.Initialize（）434
   System.Web.Services.Protocols.ServerProtocolFactory.Create（类型类型，HttpContext的背景下，Htt的prequest请求的Htt presponse响应，布尔和放大器; abortProcessing）+122

[InvalidOperationException: Method ProfileServices.My can not be reflected.] System.Web.Services.Protocols.SoapReflector.ReflectMethod(LogicalMethodInfo methodInfo, Boolean client, XmlReflectionImporter xmlImporter, SoapReflectionImporter soapImporter, String defaultNs) +6173 System.Web.Services.Description.SoapProtocolReflector.ReflectMethod() +137 System.Web.Services.Description.ProtocolReflector.ReflectBinding(ReflectedBinding reflectedBinding) +1776 System.Web.Services.Description.ProtocolReflector.Reflect() +641 System.Web.Services.Description.ServiceDescriptionReflector.ReflectInternal(ProtocolReflector[] reflectors) +685 System.Web.Services.Description.ServiceDescriptionReflector.Reflect(Type type, String url) +118 System.Web.Services.Protocols.DocumentationServerType..ctor(Type type, String uri, Boolean excludeSchemeHostPortFromCachingKey) +230 System.Web.Services.Protocols.DocumentationServerProtocol.Initialize() +434 System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type, HttpContext context, HttpRequest request, HttpResponse response, Boolean& abortProcessing) +122

[出现InvalidOperationException：无法处理请求]
   System.Web.Services.Protocols.ServerProtocolFactory.Create（类型类型，HttpContext的背景下，Htt的prequest请求的Htt presponse响应，布尔和放大器; abortProcessing）+ 320
   System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler（类型类型，HttpContext的背景下，Htt的prequest请求的Htt presponse响应）+171

[InvalidOperationException: Unable to handle request.] System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type, HttpContext context, HttpRequest request, HttpResponse response, Boolean& abortProcessing) +320 System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler(Type type, HttpContext context, HttpRequest request, HttpResponse response) +171

[出现InvalidOperationException：无法处理请求]
   System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler（类型类型，HttpContext的背景下，Htt的prequest请求的Htt $ P psponse响应$）+374
   System.Web.Services.Protocols.WebServiceHandlerFactory.GetHandler（HttpContext的背景下，动词的字符串，字符串URL，文件路径字符串）+ 209
   System.Web.Script.Services.ScriptHandlerFactory.GetHandler（HttpContext的背景下，字符串请求类型，URL字符串，字符串pathTranslated）+48
   System.Web.HttpApplication.MapHttpHandler（HttpContext的背景下，字符串的RequestType，VirtualPath路径，字符串pathTranslated，布尔useAppConfig）+226
   System.Web.MapHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute（）+145
   System.Web.HttpApplication.ExecuteStep（IExecutionStep一步，布尔和放大器; completedSynchronously）+155

[InvalidOperationException: Failed to handle request.] System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler(Type type, HttpContext context, HttpRequest request, HttpResponse response) +374 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) +48 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

推荐答案

默认情况下，的 asp.net 使用<一个href=\"http://www.asp.net/web-api/overview/formats-and-model-binding/json-and-xml-serialization#xml_media_type_formatter\"相对=nofollow> 的DataContractSerializer 序列化到XML，但错误信息不能序列成员＆LT; X＆GT;因为它是接口是的XmlSerializer code> ，所以显然你已经切换到了。

By default, asp.net uses DataContractSerializer to serialize to XML, however the error message "Cannot serialize member <x> because it is an interface" is generated by XmlSerializer, so apparently you have switched to that.

按规定你可以考虑切换回的DataContractSerializer 这里，可序列化类型的属性的IEnumerable＆LT; T＆GT; 只要底层类型 T 可序列化。

You could consider switching back to DataContractSerializer as specified here, which can serialize properties of type IEnumerable<T> as long as the underlying type T can be serialized.

另外，如果你不想这样做，你可以修改你的 ProfileObject 类返回代理阵列进行序列化，而无需更改底层设计：

Alternatively, if you don't want to do that, you could modify your ProfileObject class to return proxy arrays for serialization without changing your underlying design:

public class ProfileObject
{
    public Person Person { get; set; }

    [XmlIgnore]
    public IEnumerable<Node<Language>> Language { get; set; }

    [XmlIgnore]
    public IEnumerable<Node<Country>> Country { get; set; }

    [XmlArray("Languages")]
    [XmlArrayItem("Language")]
    [Browsable(false), EditorBrowsable(EditorBrowsableState.Never), DebuggerBrowsable(DebuggerBrowsableState.Never)]
    public Node<Language>[] LanguageArray
    {
        get
        {
            if (Language == null)
                return null;
            return Language.ToArray();
        }
        set
        {
            Language = value;
        }
    }

    [XmlArray("Countries")]
    [XmlArrayItem("Country")]
    [Browsable(false), EditorBrowsable(EditorBrowsableState.Never), DebuggerBrowsable(DebuggerBrowsableState.Never)]
    public Node<Country>[] CountryArray
    {
        get
        {
            if (Country == null)
                return null;
            return Country.ToArray();
        }
        set
        {
            Country = value;
        }
    }
}

更新

的XmlSerializer 只会序列化的公共 GET 和设置方法。由于 Node.Data 是GET-而已，它不能由的XmlSerializer 连载。

XmlSerializer will only serialize properties with public get and set methods. Since Node.Data is get-only, it can't be serialized by XmlSerializer.

由于您只需要序列化数据，而不是节点＆lt; TDATA＆GT; ，并且永远不需要反序列化，你可以使用LINQ返回改变你的节点枚举到数据序列化数组如下：

Since you only need to serialize the data and not the Node<TData>, and never need to deserialize, you can use linq to return transform your enumerable of nodes to an array of data for serialization as follows:

public static class NodeExtensions
{
    public static TData [] ToDataArray<TData>(this IEnumerable<Node<TData>> nodes)
    {
        if (nodes == null)
            return null;
        return nodes.Select(n => n.Data).ToArray();
    }
}

public class ProfileObject
{
    public Person Person { get; set; }

    [XmlIgnore]
    public IEnumerable<Node<Language>> Language { get; set; }

    [XmlIgnore]
    public IEnumerable<Node<Country>> Country { get; set; }

    [XmlArray("ArrayOfLanguage")]
    [XmlArrayItem("Language")]
    [Browsable(false), EditorBrowsable(EditorBrowsableState.Never), DebuggerBrowsable(DebuggerBrowsableState.Never)]
    public Language [] LanguageArray
    {
        get
        {
            return Language.ToDataArray();
        }
        set
        {
            throw new NotImplementedException();
        }
    }

    [XmlArray("ArrayOfCountry")]
    [XmlArrayItem("Country")]
    [Browsable(false), EditorBrowsable(EditorBrowsableState.Never), DebuggerBrowsable(DebuggerBrowsableState.Never)]
    public Country [] CountryArray
    {
        get
        {
            return Country.ToDataArray();
        }
        set
        {
            throw new NotImplementedException();
        }
    }
}

这篇关于无法序列成员＆LT; X＆GT;因为它是一个接口的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！