In C#, how can I tell whether a generic type, T, is (not implements!) an interface?

Question

Edit : I made a mistake an the premise was wrong. typeof(T).IsClass does indeed work - as does typeof(T)IsInterface, as was pointed out.

Say I have this method:

public T GetService<T>() where T : IService

I want to test whether the generic type, T, was sent into this method as an interface, rather than as a class. In other words, I want to differentiate between a call from MyClass.GetService<IService>() and MyClass.GetService<ImplementingClass>() . How can I do this?

I tried using is object , and is System.Object , but it will not make this distinction. Using typeof(T).IsClass and default(T).IsClass also don't work, because, respectively, the the System.Type return type is always a class, and because IsClass isn't available to a default T.

How else can I do this?

Answer 1

I think you can check runtime like below.

typeof(T).IsInterface

Please check this link for more details.

Answer 2

我测试了您的情况，typeof（T）。IsClass确实有效

Answer 3

It turns out my premise was wrong. This does indeed work:

typeof(T).IsClass

which returns false if an interface is specified.