C＃nameof泛型类型，不指定类型

Question

Assume I have the type

public class A<T> { }

and somewhere in the code I want to throw an exception related to incorrect usage of that type:

throw new InvalidOperationException("Cannot use A<T> like that.");

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So far, so good, but I don't want to hardcode the classes name, so I thought I could maybe use

throw new InvalidOperationException($"Cannot use {nameof(A<T>)} like that.");

instead, but in this context I don't know the exact type T . So I thought maybe I could do it with template specialization like in C++:

throw new InvalidOperationException($"Cannot use {nameof(A)} like that.");

or

throw new InvalidOperationException($"Cannot use {nameof(A<>)} like that.");

but those yield

Incorrect number of type parameters.

and

Type argument is missing.

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I absolutely don't want to hardcode the classes name for it might change later. How can I get the name of the class, preferably via nameof ?

Optimally, what I want to achieve is "Cannot use A<T> like that." or "Cannot use A like that." .

Answer 1

If you don't care about displaying T , you can just use eg nameof(A<object>) , assuming object complies with the generic type constraints.

This results in "Cannot use A like that."

If you want to print exactly A<T> , you could use:

$"{nameof(A<T>)}<{nameof(T)}>"

But only from within the class, as T does not exist elsewhere.

Answer 2

Depending on the place you want to raise that exception, you can use the type.

On the instance, call this.GetType() and then get the Name or FullName property:

throw new InvalidOperationException($"Cannot use {this.GetType().Name} like that.");

Answer 3

Have you tried:

typeof(T).FullName;

or

t.GetType().FullName;

Hope it works for you.