Why is a field in an auto-generated class serialized into an element when defined as an attribute in the XSD?

问题

I'm trying to expose a fairly complex object as XML through a REST API (using WCF).

However, the object is defined by an XSD file so I've generated classes using the xsd.exe tool. The problem is that it seems that when my object is serialized to XML, an attribute (defined in the xsd) is serialized into an element. And I don't get why. Currently, I'm assuming that my xsd somehow allows that, but I can't tell why. I don't do any custom serialization, I let the framework handle it.

Can someone explain why this is happening and how do I control the behavior?

Here the part from the xsd containing the element and attribute. Edit: the attribute in question is version

<xs:schema xmlns:b="http://some.namespace.com/" xmlns="http://someothernamespace.com/" elementFormDefault="qualified" targetNamespace="http://someothernamespace.com/" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:include schemaLocation="JobPositionPosting.xsd" />
  <xs:element name="Envelope">
    <xs:complexType>
      <xs:sequence>
        <xs:element ref="Sender" />
        <xs:element minOccurs="0" ref="TransactInfo" />
        <xs:element maxOccurs="unbounded" ref="Packet" />
      </xs:sequence>
      <xs:attribute fixed="0.52" name="version" type="xs:string" use="required" />
    </xs:complexType>
  </xs:element>

And here's the generated code.

/// <remarks/>
[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.1")]
[System.SerializableAttribute()]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true, Namespace = "<removed>")]
[System.Xml.Serialization.XmlRootAttribute(Namespace = "http://somenamespace.com", IsNullable = false)]
public partial class Envelope
{

    /// <remarks/>
    public Sender Sender;

    /// <remarks/>
    public TransactInfo TransactInfo;

    /// <remarks/>
    [System.Xml.Serialization.XmlElementAttribute("Packet")]
    public Packet[] Packet;

    /// <remarks/>
    [System.Xml.Serialization.XmlAttributeAttribute("version")]
    public string version;

    public Envelope()
    {
        this.version = "0.52";
    }
}

And here's the xml returned from the REST service, i.e. the serialized object.

<!-- (the rest o the xml is left out on purpose) -->
<Envelope>
    <senderField i:nil="true"/>
    <transactInfoField i:nil="true"/>
    <versionField>0.52</versionField>
</Envelope>

Thanks!

回答1:

xsd.exe produces classes to be used by System.Xml.Serialization.XmlSerializer, while your REST-service is using some variant of System.Runtime.Serialization.DataContractSerializer.

For DataContractSerializer, you should use svcutil.exe instead.

svcutil.exe /help
svcutil.exe schema.xsd /dconly

来源：https://stackoverflow.com/questions/11449564/why-is-a-field-in-an-auto-generated-class-serialized-into-an-element-when-define

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.net

xml-serialization

xmlserializer

xsd.exe

auto-generate