How do I call a base class implementation of an explicitly impemented interface method?

Question

I'm trying to call an explicitly implemented interface method implemented on the base class but just can't seem to get it to work. I agree the idea is ugly as hell, but I've tried every combination I can think of, to no avail. In this case, I can change the base class, but thought I'd ask the question to satisfy my general curiosity.

Any ideas?

// example interface
interface MyInterface
{
    bool DoSomething();
}

// BaseClass explicitly implements the interface
public class BaseClass : MyInterface
{
    bool MyInterface.DoSomething()
    {
    }
}

// Derived class 
public class DerivedClass : BaseClass
{
    // Also explicitly implements interface
    bool MyInterface.DoSomething()
    {
        // I wish to call the base class' implementation
        // of DoSomething here
        ((MyInterface)(base as BaseClass)).DoSomething(); // does not work - "base not valid in context"
    }
}

Answer 1

You cannot (it is not part of the interface available to subclasses). In that scenario, use something like:

// base class
bool MyInterface.DoSomething()
{
    return DoSomething();
}
protected bool DoSomething() {...}

Then any subclass can call the protected DoSomething(), or (better):

protected virtual bool DoSomething() {...}

Now it can just override rather than re-implement the interface:

public class DerivedClass : BaseClass
{
    protected override bool DoSomething()
    {
        // changed version, perhaps calling base.DoSomething();
    }
}