为什么在映射具有相同名称但不同名称空间的类的对象图时，XmlSerializer无法初始化？

Question

I'm receiving XML from a third party that has no namespaces. The XML schema, in a simplified and obfuscated form, looks like the following:

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

Please take note that there are two distinct Address classes here. These are actually defined as two different complexType s, each in a spearate XML schema which I have received from the third party. One schema reflects the Root model, while the other schema reflects the model for ReportAReport Each Address class has distinct properties.

I represent each in a namespace, treating each XML schema as its own namespace. In fact, the schemas have namespaces defined, but the XML response I receive from the third party has chosen to omit these namespaces for some reason.

Namespace: 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; }
    }
}

Namespace: MyCompany.MyProject.ReportA

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

    public class Address
    {
        public string Zip { get; set; }
    }
}

The exception I'm getting is as follows:

Result Message: Unable to create instance of class MyCompany.MyProject.Test.AggregatorTests. Error: System.TypeInitializationException: The type initializer for 'MyCompany.MyProject.Test.AggregatorTests' threw an exception. ---> System.InvalidOperationException: There was an error reflecting type 'MyCompany.MyProject.Root'. ---> System.InvalidOperationException: There was an error reflecting property 'ReportAReport'. ---> System.InvalidOperationException: There was an error reflecting type 'MyCompany.MyProject.ReportA.ReportAReport'. ---> System.InvalidOperationException: There was an error reflecting property 'Address'. ---> System.InvalidOperationException: There was an error reflecting type 'MyCompany.MyProject.ReportA.Address'. ---> System.InvalidOperationException: Types 'MyCompany.MyProject.ReportA.Address' and 'MyCompany.MyProject.Address' both use the XML type name, 'Address', from namespace ''. Use XML attributes to specify a unique XML name and/or namespace for the type..

The line to which this exception is referring is as follows:

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

The exception seems to be fairly clear about what is happening. The XmlSerializer is failing to understand to which Address class to map the property 'Address' in the ReportAReport class.

What I can't understand is why it is failing to understand to which Address class to map the property. In the class definition of ReportAReport , the 'Address' property is declared as being of type MyCompany.MyProject.ReportA.Address .

I even tried using XmlElementAttribute to specify the Type on ReportAReport :

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

Though, that seems fairly redundant anyways...

Question

The compiler clearly knows that Address here is referring to MyCompany.MyProject.ReportA.Address . Why is the XmlSerializer unable to make this discernment?

Shouldn't XmlSerializer know that if it encounters an Address node within a ReportAReport node, that it is of type MyCompany.MyProject.ReportA.Address rather than MyCompany.MyProject.Address ?

What am I missing here?

---

I added the stack trace because it shows where the XmlSerializer initialization process is hiccuping. I actually pulled this stack trace from my real world example, which has a few nodes deeper than the samples, so there might be a few levels of recursion in the stack trace that don't seem to line up with the sample code I've provided.

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()

---

Update: I completely rewrote this question after realizing that my initial assessment about the exceptions I was receiving was completely incorrect. I negligently assumed that deserialization was the cause of the exception I was receiving, when in fact, it was clearly stated that initialization of the XmlSerializer was the problem. The question has been edited to state this fact, and I'm wiping the cake off my face as we speak. I apologize to anyone I misled with initial faulty and incomplete information.

Answer 1

try this model to de-serialize against. You can instantiate a new Address of either type and set the value from the deserialized model. You could use AutoMapper to accomplish the copy of objects

    /// <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;
            }
        }
    }