Question

class Program
    {
        static void Main(string[] args)
        {
            List<A> myList = new List<A> {new A(), new B(), new C()};

            foreach (var a in myList)
            {
                Render(a);
            }

            Console.ReadKey();
        }

        private static void Render(A o)
        {
            Console.Write("A");
        }

        private static void Render(B b)
        {
            Console.Write("B");
        }

        private static void Render(C c)
        {
            Console.Write("C");
        }
    }

    class A
    {

    }

    class B : A
    {

    }

    class C : A
    {

    }

The output is: AAA

Is it possible to somehow use method overloading, so that the output would be: ABC?

Answer 1

You can use dynamic typing if you’re using C# 4:

foreach (dynamic a in myList)
{
    Render(a);
}

Within static typing, overload resolution is performed at compile-time, not at execution time.

For the implementation to be chosen at decision time, you either have to use overriding instead of overloading, or use dynamic typing as above.