返回自定义类的WCF服务在Reference.cs中生成错误

Question

I have a WCF Service project in Visual Studio 2008 that contains about 12 methods, some of which return primitive types like bool or string. I also have a Visual Studio Unit Test Project that references the published WCF Service. The Test Project compiles successfully when all the return types are primitive.

If I add a new method to the service that returns a custom class, publish it and update the service reference in the Test Project, it doesn't compile. The errors are: -

1. The type 'PublisherFaultException' already contains a definition for 'Reason'.
2. The type 'PublisherFaultException' already contains a definition for 'PropertyChanged'.
3. Type 'Publisher.Test.LibraryReference.PublisherFaultException' already defines a member called 'RaisePropertyChanged' with the same parameter types.

all in the auto-generated reference.cs file.

The contract for the method of the WCF Service is: -

Page GetItem(string path);

and the Page class has the DataContract attribute and it's public properties have the DataMember attribute.

I'm reluctant to modify the Reference.cs file as I'll need to do this every time the Service is updated.

Anyone know why this is happening?

Stuart.

Answer 1

When you Add Service Reference, you get a 'reuse types in assembly' option - this is likely to be the key to sorting out the duplication.

Or do you have some Test References that are causing the duplication?

Also, have a look in the References section of the project tree and see if there is anything unexpected in there (do you have references to 2 assemblies that both contain Service References in the same namespace?).

Answer 2

Using auto-generated proxy class it is always pain.

To handle situation like this I using separate assembly with data contract classes and service interface.

Contract dll will have:

public interface IService
{
    [OperationContract]
    List GetContentList();
}

[DataContract]
public class ContentItem
{
  [DataMember] public string Name;
  [DataMember] public object Data;
}

The client will have reference to the Contract.dll. Proxy will be created manually:

class ServiceProxy : ClientBase<IService>, IService
 {
  public List GetContentList()
  {
   return Channel.GetContentList();
  }
 }

The server dll will have reference to the same Contract dll. So we will be able to avoid any errors with auto generated proxy. Also the manually created proxy will be simpler, more manageable.

Answer 3

When adding the Service Reference, try clicking Advanced, and select "Generate asynchronous operations".

I think what was happening was that there were some asynchronous methods in the web service, with names ending in "Async", which would conflict with the methods generated in the References.cs.

eg imagine the web service contains 2 methods: (1) SayHello and (2) SayHelloAsync .

Generating using the default task-based method produces:

• SayHello and SayHelloAsync for (1)
• SayHelloAsync and SayHelloAsyncAsync for (2).

The conflict occurred because there were 2 generated methods called SayHelloAsync .

At least I think that's what was going on. Anyway setting "Generate asynchronous operations" worked for me.