WCF will not return an int

Question

I am building a WCF in C#, and a client to consume it at the same time. For some reason I am having trouble getting a method to return an int. Here is my contract:

Answer 1

Can you import it as a Service Reference (newer tech) instead of a Web Reference (older tech)? I work with WCF services through service references and haven't seen such an issue - I've only seen a Specified property (and that as a property alongside the int, not as two out params) when the service definition allows no int to be specified (WCF-generated service definitions have, in my experience, worked as expected).

If you can't find a better solution, here's a workaround using partial classes: (this would have to be done any time you return a struct, not just ints)

public partial class MData
{
    public int ReturnAnInt()
    {
        int result;
        bool specified;
        this.ReturnAnInt(out result, out specified);
        if (!specified) throw new InvalidOperationException();
        return result;
    }
}

Update http://www.codeproject.com/Articles/323097/WCF-ASMX-Interoperability-Removing-the-Annoying-xx has a (somewhat klunky) solution, and informs us that the root cause is that WCF generates poor (arguably inaccurate) WSDLs - they have a minOccurs="0" on elements that really don't need it. Web References reads this as-is, and generates klunky code to deal with it, which is what you're trying to deal with. Based on his article, you can return this type instead of an int:

[MessageContract(IsWrapped = false)]
public class MyInt
{
    [MessageBodyMember]
    public int Result { get; set; }

    public static implicit operator MyInt(int i)
    {
        return new MyInt { Result = i };
    }

    public static implicit operator int(MyInt m)
    {
        return m.Result;
    }
}

Along with modifying the return type of the method:

[ServiceContract]
public interface IMData
{
    [OperationContract]
    MyInt ReturnAnInt();

    [OperationContract]
    String HelloWorld();
}
public class Service1 : IMData
{
    public MyInt ReturnAnInt()
    {
        return 4;
    }

    public string HelloWorld()
    {
        return "Hello World";
    }
}