Question

Today I happens to find that one C# class can inherit one interface both in implicit and explicit way. This surprises me. If C# works in this way, then one instance can behave differently when referenced in different way.

interface IFoo {     void DoSomething(); }  class Foo : IFoo {     #region IFoo Members     public void DoSomething()     {         Console.WriteLine('do something implicitly');     }     #endregion      #region IFoo Members     void IFoo.DoSomething()     {         Console.WriteLine('do something explicitly');     }     #endregion }           Foo f = new Foo();         f.DoSomething();          ((IFoo)f).DoSomething(); 

Above code runs and output

do something implicitly do something explicitly 

I believe that this design of C# make inconsistency of behavior. Perhaps it is mandatory that one C# class can inherit from one interface in implicit or expliict way, but not both.

Is there any reason that why C# is designed in such a way?

Answer 1

Your example does not implement IFoo both implicitly and explicitly. You only implement IFoo.DoSometing() explicitly. You have a new method on your class called DoSomething(). It has nothing to do with IFoo.DoSomething, except that it has the same name and parameters.