WCF and IList of ISomething

Question

I'm wondering how to make this object available through WCF:

[DataContract]
public class A : IA
{
    [DataMember]
    public List<IB> ListOfB { get; set; } 
}

public interface IA
{
    List<IB> ListOfB { get; set; }
}

with IB interface of class B.

Generated XSD is:

<xs:complexType name="A">
  <xs:sequence>
    <xs:element xmlns:q1="http://schemas.microsoft.com/2003/10/Serialization/Arrays" minOccurs="0" name="ListOfB" nillable="true" type="q1:ArrayOfanyType"/>
  </xs:sequence>
</xs:complexType>
<xs:element name="A" nillable="true" type="tns:A"/>
</xs:schema>

ArrayOfanyType -> I'm feeling that it can't work since IB can't be tagged [DataContract].

Answer 1

For the serializer to interpret your contract they need to be expressed in terms of concrete types rather than interfaces. If you change your code to this (and annotate class B with the appropriate DataContract and DataMember attributes, you should be good to go.

[DataContract]
public class A
{
    [DataMember]
    public List<B> ListOfB { get; set; } 
}