.NET C# Explicit implementation of grandparent's interface method in the parent interface

Question

That title's a mouthful, isn't it?...

Here's what I'm trying to do:

public interface IBar {
     void Bar();
}
public interface IFoo: IBar {
    void Foo();
}
public class FooImpl: IFoo {
    void IFoo.Foo()   { /* works as expected */ }
    //void IFoo.Bar() { /* i'd like to do this, but it doesn't compile */ }

    //so I'm forced to use this instead:
    void IBar.Bar()   { /* this would compile */ }
}

My problem with this is that it's... inconvenient to call Bar():

IFoo myFoo = new FooImpl();
//myFoo.Bar(); /* doesn't compile */
((IBar)myFoo).Bar(); /* works, but it's not necessarily obvious 
                        that FooImpl is also an IBar */

So... Is there a way to declare IFoo.Bar(){...} in my class, other than basically merging the two interfaces into one?

And, if not, why?

Answer 1

It's possible to use the new keyword in an interface to explicitly hide a member declared in the interface it extends:

public interface IBar
{
    void Bar();
}

public interface IFoo:IBar
{
    void Foo();
    new void Bar();
}

public class Class1 : IFoo
{
    void Bar(){}

    void IFoo.Foo(){}

    void IFoo.Bar(){}

    void IBar.Bar(){}
}

Answer 2

You don't have two implementations of IFoo; you only have one.
The CLR does not distinguish between copies of interfaces that come from different points in the interface tree.

In particular, there is no way to call IFoo.Bar(); you can only call IBar.Bar.
If you add a separate Bar() method to IFoo, your code will work.