Question

I have the following code snippet

Class Parent
{
    public override String ToString()
    {
            return "in Parent";
    }

    public virtual void printer()
    {
           Console.write(this.ToString());
    }
}

Class Child : Parent
{
    public override String ToString()
    {
            return "in Derived";
    }

    public override void printer()
    { 
           base.printer();
           Console.write(this.ToString());
    }
}

in Main I have

Parent p = new Derived();
p.printer();

The output comes as “In Derived” 2 times. This is expected as most overridden method is called.

But, is it possible to call the ToString() method of the base class, in this case instead of the base calling the derived one?

Answer 1

No. Form MSDN:

When a virtual method is invoked, the run-time type of the object is
checked for an overriding member. The overriding member in the most
derived class is called, which might be the original member, if no
derived class has overridden the member.

So even if you cast to Parent, the object is still a Child so that override will apply. The problem is that you’re calling ToString() from the parent class which has been overridden, so there’s no way to get to it if the instance is a Child.

One way to get around it is to create a separate private function instead of using ToString():

public class Parent
{
    public override String ToString()
    {
        return ToStringPrivate();
    }

    private string ToStringPrivate()
    {
        return "in Parent";
    }

    public virtual void printer()
    {
        Console.WriteLine(this.ToStringPrivate());
    }
}

public class Child : Parent
{
    public override String ToString()
    {
        return "in Derived";
    }

    public override void printer()
    {
        base.printer();
        Console.WriteLine(this.ToString());
    }
}