为什么 XmlSerializer 在映射具有相同名称但不同命名空间的类的对象图时无法初始化

本文关键字：命名空间 对象图 初始化 映射 XmlSerializer 为什么 | 更新日期: 2023-09-27 17:59:44

>我正在从没有命名空间的第三方接收XML。XML 架构采用简化和模糊处理的形式，如下所示：

<Root>
    <Address>
        <PostalCode>57373</PostalCode>
    </Address>
    <ReportAReport>
        <Address>
            <Zip>18573</Zip>
        </Address>
    </ReportAReport>
</Root>

请注意，这里有两个不同的Address类。这些实际上被定义为两个不同的complexType，每个都在我从第三方收到的矛状XML模式中。一个架构反映Root模型，而另一个架构反映ReportAReport 每个Address类都有不同的属性。

我在命名空间中表示每个架构，将每个 XML 架构视为自己的命名空间。事实上，模式定义了命名空间，但是由于某种原因，我从第三方收到的 XML 响应选择省略这些命名空间。

命名空间：MyCompany.MyProject

namespace MyCompany.MyProject
{
    public class Root
    {
        public Address Address { get; set; }
        public ReportAReport ReportAReport { get; set; }
    }
    public class Address
    {
        public string PostalCode { get; set; }
    }
}

命名空间：MyCompany.MyProject.ReportA

namespace MyCompany.MyProject.ReportA
{
    public class ReportAReport
    {
        public Address Address { get; set; }
    }
    public class Address
    {
        public string Zip { get; set; }
    }
}

我得到的异常如下：

结果消息：无法创建类的实例 MyCompany.MyProject.Test.AggregatorTests. 错误： System.TypeInitializationException：的类型初始值设定项 'MyCompany.MyProject.Test.AggregatorTests'抛出了一个异常。---> 系统无效操作异常：反映类型时出错 "我的公司.我的项目.根"。---> System.InvalidOperationException： 存在反映属性"ReportAReport"的错误。---> 系统无效操作异常：反映类型时出错 'MyCompany.MyProject.ReportA.ReportAReport'.---> 系统无效操作异常：有一个错误反映 属性"地址"。---> System.InvalidOperationException： 有 反映类型"MyCompany.MyProject.ReportA.Address"的错误。---> 系统无效操作异常：类型 "MyCompany.MyProject.ReportA.Address"和"MyCompany.MyProject.ReportA.Address"和 "MyCompany.MyProject.Address"都使用XML类型名称"Address"， 从命名空间 ''。使用 XML 属性指定唯一的 XML 名称 和/或类型的命名空间。

此异常所指的行如下所示：

XmlSerializer serializer = new XmlSerializer(typeof(Root));

例外似乎对正在发生的事情相当清楚。XmlSerializer无法理解将ReportAReport类中的属性"Address"映射到哪个类Address。

我不明白的是为什么它无法理解将属性映射到哪个Address类。在 ReportAReport 的类定义中，"Address" 属性被声明为类型 MyCompany.MyProject.ReportA.Address。

我什至尝试使用 XmlElementAttribute 来指定ReportAReport上的Type：

[XmlElement(Type = typeof(Address))]
public Address Address { get; set; }

不过，无论如何，这似乎相当多余...

问题

编译器清楚地知道Address这里指的是MyCompany.MyProject.ReportA.Address。为什么XmlSerializer无法做出这种辨识？

XmlSerializer不应该知道，如果它在ReportAReport节点中遇到Address节点，它是MyCompany.MyProject.ReportA.Address类型而不是MyCompany.MyProject.Address？

我在这里错过了什么？

我添加了堆栈跟踪，因为它显示了 XmlSerializer 初始化过程打嗝的位置。我实际上从我的真实示例中提取了此堆栈跟踪，该示例具有比示例更深的节点，因此堆栈跟踪中可能存在一些级别的递归，这些递归似乎与我提供的示例代码不一致。

Result StackTrace:  
at System.Xml.Serialization.XmlReflectionImporter.GetTypeMapping(String typeName, String ns, TypeDesc typeDesc, NameTable typeLib, Type type)
   at System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping(StructModel model, String ns, Boolean openModel, XmlAttributes a, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportAccessorMapping(MemberMapping accessor, FieldModel model, XmlAttributes a, String ns, Type choiceIdentifierType, Boolean rpc, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportFieldMapping(StructModel parent, FieldModel model, XmlAttributes a, String ns, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping(StructModel model, String ns, Boolean openModel, XmlAttributes a, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportAccessorMapping(MemberMapping accessor, FieldModel model, XmlAttributes a, String ns, Type choiceIdentifierType, Boolean rpc, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportFieldMapping(StructModel parent, FieldModel model, XmlAttributes a, String ns, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping(StructModel model, String ns, Boolean openModel, XmlAttributes a, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.CreateArrayElementsFromAttributes(ArrayMapping arrayMapping, XmlArrayItemAttributes attributes, Type arrayElementType, String arrayElementNs, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportArrayLikeMapping(ArrayModel model, String ns, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportAccessorMapping(MemberMapping accessor, FieldModel model, XmlAttributes a, String ns, Type choiceIdentifierType, Boolean rpc, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportFieldMapping(StructModel parent, FieldModel model, XmlAttributes a, String ns, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping(StructModel model, String ns, Boolean openModel, XmlAttributes a, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportAccessorMapping(MemberMapping accessor, FieldModel model, XmlAttributes a, String ns, Type choiceIdentifierType, Boolean rpc, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportFieldMapping(StructModel parent, FieldModel model, XmlAttributes a, String ns, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping(StructModel model, String ns, Boolean openModel, XmlAttributes a, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportAccessorMapping(MemberMapping accessor, FieldModel model, XmlAttributes a, String ns, Type choiceIdentifierType, Boolean rpc, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportFieldMapping(StructModel parent, FieldModel model, XmlAttributes a, String ns, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping(StructModel model, String ns, Boolean openModel, XmlAttributes a, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportAccessorMapping(MemberMapping accessor, FieldModel model, XmlAttributes a, String ns, Type choiceIdentifierType, Boolean rpc, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportFieldMapping(StructModel parent, FieldModel model, XmlAttributes a, String ns, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping(StructModel model, String ns, Boolean openModel, XmlAttributes a, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.CreateArrayElementsFromAttributes(ArrayMapping arrayMapping, XmlArrayItemAttributes attributes, Type arrayElementType, String arrayElementNs, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportArrayLikeMapping(ArrayModel model, String ns, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportAccessorMapping(MemberMapping accessor, FieldModel model, XmlAttributes a, String ns, Type choiceIdentifierType, Boolean rpc, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportFieldMapping(StructModel parent, FieldModel model, XmlAttributes a, String ns, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.InitializeStructMembers(StructMapping mapping, StructModel model, Boolean openModel, String typeName, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportStructLikeMapping(StructModel model, String ns, Boolean openModel, XmlAttributes a, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
 --- End of inner exception stack trace ---
    at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(TypeModel model, String ns, ImportContext context, String dataType, XmlAttributes a, Boolean repeats, Boolean openModel, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportElement(TypeModel model, XmlRootAttribute root, String defaultNamespace, RecursionLimiter limiter)
   at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(Type type, XmlRootAttribute root, String defaultNamespace)
   at System.Xml.Serialization.XmlSerializer..ctor(Type type, String defaultNamespace)
   at System.Xml.Serialization.XmlSerializer..ctor(Type type)
   at MyCompany.MyProject.Test.AggregatorTests..cctor() in c:'Users'crush'Documents'Visual Studio 2012'Projects'MyCompany.MyProject'Test'MyCompany.MyProject.Test'AggregatorTests.cs:line 16
 --- End of inner exception stack trace ---
    at MyCompany.MyProject.Test.AggregatorTests..ctor()

更新：在意识到我对收到的异常的初步评估完全不正确后，我完全重写了这个问题。我疏忽地认为反序列化是我收到异常的原因，而实际上，它清楚地表明XmlSerializer的初始化是问题所在。这个问题已经被编辑以陈述这个事实，在我们说话的时候，我正在擦掉脸上的蛋糕。我向任何被最初错误和不完整的信息误导的人道歉。

为什么 XmlSerializer 在映射具有相同名称但不同命名空间的类的对象图时无法初始化

尝试此模型进行反序列化。您可以实例化任一类型的新地址，并从反序列化模型中设置值。您可以使用自动映射器来完成对象的复制

    /// <remarks/>
    [System.SerializableAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    [System.Xml.Serialization.XmlRootAttribute(Namespace = "", IsNullable = false)]
    public partial class Root
    {
        private RootAddress addressField;
        private RootReportAReport reportAReportField;
        /// <remarks/>
        public RootAddress Address
        {
            get
            {
                return this.addressField;
            }
            set
            {
                this.addressField = value;
            }
        }
        /// <remarks/>
        public RootReportAReport ReportAReport
        {
            get
            {
                return this.reportAReportField;
            }
            set
            {
                this.reportAReportField = value;
            }
        }
    }
    /// <remarks/>
    [System.SerializableAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    public partial class RootAddress
    {
        private ushort postalCodeField;
        /// <remarks/>
        public ushort PostalCode
        {
            get
            {
                return this.postalCodeField;
            }
            set
            {
                this.postalCodeField = value;
            }
        }
    }
    /// <remarks/>
    [System.SerializableAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    public partial class RootReportAReport
    {
        private RootReportAReportAddress addressField;
        /// <remarks/>
        public RootReportAReportAddress Address
        {
            get
            {
                return this.addressField;
            }
            set
            {
                this.addressField = value;
            }
        }
    }
    /// <remarks/>
    [System.SerializableAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    public partial class RootReportAReportAddress
    {
        private ushort zipField;
        /// <remarks/>
        public ushort Zip
        {
            get
            {
                return this.zipField;
            }
            set
            {
                this.zipField = value;
            }
        }
    }
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