Why does dynamic binding fail when using interface inheritance?

Question

In C#, please does anyone know why I can\'t do the following? (specifically the line marked \'NOT fine!\' below)

interface A
{
    void Add(dynamic entity);
         


        

Answer 1

Looking on Microsoft Connect it's filed as a bug - Dynamic runtime fails to find method from a base interface during runtime

Answer 2

It looks like the multiple layers of interface inheritance are doing in the passing of a dynamic type variable. It's definitely tripping up the run time binding.

At this point if you're looking to get it to work a possible workaround is:

dynamic x = 23;
b.Add((object)x);

dynamic y = "Hello, World!";
b.Add((object)y);

Since dynamic is seen as object by the IL, so casting everything explicitly to type object will get this to work for you.