Call derived class method from within base class?

Question

I am trying to have a non-virtual base class method call a derived method that overrides one of the base class's virtual methods. For the life of me, I can't get it to work. See the code below:

public ref class BaseClass
{
    virtual void OverriddenMethod(){}

    void Run()
    {
        // Do some initial work here.

        // Call the derived class's version of OverridenMethod to do final work:
        OverriddenMethod();
    }
};

public ref class DerivedClass : public BaseClass
{
    virtual void OverriddenMethod() override
    {
        // Do some final work here.
    }
};

int main()
{
    DerivedClass^ DC = gcnew DerivedClass();
    DC->Run();
}

Using the code above, the base class's OverriddenMethod() gets called instead of the derived class's OverriddenMethod(), which isn't what I want. I was under the impression that, when using polymorphism, a call to a base class method that is overridden should instead call the overriding method of the derived class.

I have also tried using abstract:

public ref class BaseClass abstract
{
    virtual void OverriddenMethod() abstract;

    void Run()
    {
        // Do some initial work here.

        // Call the derived class's version of OverridenMethod to do final work:
        OverriddenMethod();
    }
};

public ref class DerivedClass : public BaseClass
{
    void OverriddenMethod()
    {
        // Do some final work here.
    }
};

int main()
{
    DerivedClass^ DC = gcnew DerivedClass();
    DC->Run();
}

But this gives a C3278 compiler error (direct call of interface method 'interface method' will fail at runtime) when OverriddenMethod is called inside of the BaseClass::Run() definition.

Answer 1

Solution by OP.

public ref class BaseClass abstract
{
    virtual void BaseClass::OverriddenMethod() abstract;

    void BaseClass::Run()
    {
        // Do some initial work here.

        // Call the derived class's version of OverridenMethod to do final work:
        BaseClass::OverriddenMethod();  // DONT DO THIS!!!!!!!!
        OverriddenMethod(); // DO THIS INSTEAD!!!!!
    }
};

The issue here was because I was using a header for definitions and a cpp file for implementations of my base class. In the cpp file, I typically use ClassName::MemberName notation to refer to any of ClassName's members. However, doing so in this case forces the base class's virtual method to get called instead of the overridden method in the derived class.

This is why, when using the abstract keyword, I was getting the C3278 error when calling OverriddenMethod() inside of the Run() definition of the base class. Its because I was calling BaseClass::OverriddenMethod(), which points to nothing but an abstract definition.