Question

I have

class A
{}

class B : A
{}

I also have a method that expects a List parameter

void AMethod(List<A> parameter)
{}

Why can’t I

List<B> bs = new List<B>();
AMethod(bs);

And secondly what is the most elegant way to make this work?

regards

Answer 1

You could make the method signature generic like this:

void AMethod<T>(List<T> parameter) where T : A
{}

Or, you could wait for .NET 4 where this scenario is supported for IEnumerable<>