DataContractSerializer 将接口属性序列化为 System.Object / anyType

Question

在应用程序中，我具有以下接口/实现结构：

public interface IMyInterface
{
  IMyOtherInterface InstanceOfMyOtherInterface { get; }
}

public interface IMyOtherInterface
{
  string SomeValue { get; }
}

[DataContract(Name = "MyInterfaceImplementation", Namespace = "")]
public class MyInterfaceImplementation : IMyInterface
{
  [DataMember(EmitDefaultValue = false), XmlAttribute(Namespace = "")]
  public IMyOtherInterface InstanceOfMyOtherInterface { get; private set; }

  public MyInterfaceImplementation()
  {
    this.InstanceOfMyOtherInterface = new MyOtherInterfaceImplementation("Hello World");
  }
}

[DataContract(Name = "MyOtherInterfaceImplementation", Namespace = "")]
public class MyOtherInterfaceImplementation : IMyOtherInterface
{
  [DataMember]
  public string SomeValue { get; private set; }

  public MyOtherInterfaceImplementation(string value)
  {
    this.SomeValue = value; 
  }
}

现在，每当我使用 .Net DataContractSerializer 将其序列化（在我的情况下为字符串）时，如下所示：

var dataContractSerializer = new DataContractSerializer(typeof(MyInterfaceImplementation));
var stringBuilder = new StringBuilder();
using (var xmlWriter = XmlWriter.Create(stringBuilder, new XmlWriterSettings { Indent = true, Encoding = Encoding.UTF8 }))
{
  dataContractSerializer.WriteObject(xmlWriter, this);
}
var stringValue = stringBuilder.ToString();

生成的 xml 看起来很像这样：

<?xml version="1.0" encoding="utf-16"?>
<z:anyType xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="" i:type="MyInterfaceImplementation" xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/">
  <InstanceOfMyOtherInterface xmlns="" i:type="InstanceOfMyOtherInterface">
    <SomeValue>Hello World</SomeValue>
  </InstanceOfMyOtherInterface>
</z:anyType>

这些 *anyType* 似乎来自 datacontractserializer 将 MyInterfaceImplementation 实例序列化为 System.Object，与其他接口属性类似。

如果我在我的接口及其实现中使用了具体类型，如下所示：

public interface IMyInterface
{
  MyOtherInterface InstanceOfMyOtherInterface { get; }
}

..它工作得“很好” - datacontractserializer 确实创建

<MyInterfaceImplementation>...</MyInterfaceImplementation>

...nodes 而不是 z:anyType 的，但我不想/不能改变我的接口的属性。在这种情况下，有没有办法控制或帮助数据契约序列化程序？