Declare C# Class That Implements a Generic Interface

Question

Suppose I have an empty interface class IBaseInterface which is used only to "label" implementing classes as being interfaces themselves.

Is there any way to do something like this?

For example:

public class MyClass : T where T : IBaseInterface
{
}

In .NET you better use attributes instead of empty interfaces if you just want to tag/mark a class for a specific behaviour. — Caspar Kleijne, Jul 09 '11 at 20:43

score 2 · Answer 1 · answered Jul 09 '11 at 20:39

2

Not like that, there isn't. I would strongly recommend using a composition pattern to try and achieve whatever you're trying. As an alternative, you might find DynamicProxy (or some other proxy solution) is what you're going for.

answered Jul 09 '11 at 20:39

Daniel Moore

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score 2 · Accepted Answer · answered Jul 09 '11 at 20:39

2

No, you can't do that, since the compiler has to know which interface the class implements when you declare the class. You can have generic parameters to the interface, but the actual interface has to be specified.

answered Jul 09 '11 at 20:39

Lasse V. Karlsen

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score 0 · Answer 3 · answered Jul 09 '11 at 20:45

The type you're declaring isn't even generic. Something like this:

class MyClass<T> : T where T : IBaseInterface

could work under some circumstances (for example, if C++ templates were used instead of .Net generics), but it's simply not valid C# code.

I'm not sure what are the “labels” used for, but an interface with a property

ClassType ClassType { get; }

where ClassType is an enum could work.

Declare C# Class That Implements a Generic Interface

3 Answers3