Ambiguous reference in WCF and client application

Question

I've managed to reproduce one of the errors in a test project with a similar structure to my production code. It consists of three simple projects:

Common (class library):

namespace Common
{
    public enum PrimaryColor
    {
        Red,
        Green,
        Blue
    };
}

Library (WCF service library), which has a reference to Common:

using Common;

namespace Library
{
    [ServiceContract]
    public interface ILibrary
    {
        [OperationContract]
        PrimaryColor GetColor();
    }

    public class Library : ILibrary
    {
        public PrimaryColor GetColor()
        {
            return PrimaryColor.Red;
        }
    }
}

ClientApp (console application), which has a reference to Common, and a service reference to Library called "LibraryServiceReference":

using Common;
using ClientApp.LibraryServiceReference;

namespace ClientApp
{
    class Program
    {
        static void Main(string[] args)
        {
            LibraryClient client = new LibraryClient("WSHttpBinding_ILibrary");
            PrimaryColor color = client.GetColor();
        }
    }
}

The app.config files in ClientApp and Library are auto-generated and I have not modified them, and I have not changed the default configuration for the LibraryServiceReference in ClientApp.

When I compile this solution, I get the following errors in the ClientApp project:

Error 1

'PrimaryColor' is an ambiguous reference between 'Common.PrimaryColor' and 'ClientApp.LibraryServiceReference.PrimaryColor'

Error 2

Cannot implicitly convert type 'ClientApp.LibraryServiceReference.PrimaryColor' to 'Common.PrimaryColor'. An explicit conversion exists (are you missing a cast?)

please help me to fix this.

Answer 1

Make sure that 'Reuse types in all referenced assemblies' is selected in the Advanced options of Add service reference or Configure Service Reference.

Answer 2

it's because you're building x64 not "AnyCpu". I am running across this right now, and am trying to figure out if it's a bug, or if it's expected behavior.

Answer 3

1. Decorate your enum like this:

   namespace Common
   {
       [DataContract]
       public enum PrimaryColor
       {
           [EnumMember]
           Red,
           [EnumMember]
           Green,
           [EnumMember]
           Blue
       };
   }
   

2. Update Your service reference (with checking reuse types just like Mark stated).

3. Rebuild your client code.