在多个服务和.net版本之间重用类型

Question

I have Services (Service1, Service2, ...) all which reference a Common.dll all of which are in .Net 4.0 , and I am having trouble reusing the types in the consumer of the service.

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Common.dll has

Identifier {
    int Id;
    string Type;
}

Each Service implements

byte[] Get(Common.Identifier);
string Test();

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The consumer of the service ( .Net3.5 ) generates code in reference.cs

class Service1 {
    byte[] Get(Service1.Identifier);
    string Test();  
}

class Service2 {
    byte[] Get(Service2.Identifier);
    string Test();  
}

---

I tied them together by creating an Interface Adding the interface to partial classes, but can only get it to work for the Test() call

public interface IService {
    //byte[] Get(Service2.Identifier);
    string Test();  
}

public partial class Service1 : IService;
public partial class Service2 : IService;

---

This way I can use the services interchangably. I plan on creating many more to use as basically plugins to integrate to different systems

IService GetService(string provider) {
    switch (provider) {
        case "Service1":
            return (IService)new Service1();

        case "Service2":
            return (IService)new Service2();
    }
}

GetService.Test() //works perfectly.

---

My problem is how do I define, decorate "Identifier" in such a way that will allow me to use the Get(?? Identifier) without writing a bunch of code.

The only way I can think of right now is to create an interface IIdentifier, and then add to the partial classes

public partial class Service1 : IService {
    byte[] Get(IIdentifier id) {
        return this.Get(new Service1.Identifier() { Id = id.Id, Type = id.Type});
}

but there are a lot of calls and I don't want to have to wrap them all. I'm sure I'm just missing something simple, thanks for any help that can be provided.

Answer 1

I was approaching this from the wrong side, and the way I was trying to do it wouldn't work as Alexei pointed out.

I managed to get everything to work and reuse the classes in the common.dll by compiling it for .net 3.5 instead of 4.0.

.Net 4.0 is backwards compatible with 3.5 so I was able to reference the 3.5 common.dll from my services which allowed my 3.5 code to reference common.dll and thus reuse the types.

Answer 2

C# does not provide a way to use different types as the same type even if members are identical in your particular case. To fix you would need to either rewrite your services to use shared class or map classes into each other, possibly adding extension methods to make code look as if Get accepts the same type.

If you would not need to pass unique parameters but just call non-virtual/non-interface method you could have used dynamic ( dynamic service = ....; service.Get(); ) which is closest to duck typing as you can get here.