I'm not expert, in anybody's book, but I believe you're trying to use an
interface like a base class. An interface is really just a signature, a
template if you will. It does not represent inheritance. Trying to cast an
object to it's interface well, that would be like trying to turn a person
into a painting. It can't be done without breaking a few laws of nature not
to mention Newtonian physics. But you can turn a person into a child, or
senior citizen or mammal or vertebrate. A picture of a person is really just
a plan, a image of a three dimensional entity.

Try not using an interface as a generics type. Below was my testing rig.

But I maybe way off here.

DC


//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
using System;
using System.Collections.Generic;
using System.Text;

namespace InterfaceTesting
{
class Program
{
static void Main(string[] args)
{
System.Console.WriteLine("Testing Inheritance");

Manager m1 = new Manager();
m1.Name = "Manager M1";
System.Console.WriteLine("1:" + m1.Name);

Person p1 = (Person)m1;
System.Console.WriteLine("2:" + p1.Name);

List<Manager> Managers = new List<Manager>();

List<Person> Persons = new List<Person>();

List<Pet> Pets = new List<Pet>();

Manager m2 = new Manager();
m2.Name = "Manager M2";

Managers.Add(m2);

Persons.Add(m2);

//Pets.Add(m2); // although Pet implements IMammal you can't
turn a manager into a pet - as much as we'd like to sometimes.

System.Threading.Thread.CurrentThread.Suspend();
}
}

interface IMammal
{
}

class Pet : IMammal
{
public string Name = String.Empty;
}

class Person : IMammal
{
public string Name = String.Empty;
}

class Manager : Person
{
public string Title = String.Empty;
}
}


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