c# - Override method from instance of the class

Question

I have a merly simple question, but seems cant find an answer for it, I want to know if its possible to override a method from a instance class structore would look like this:

public class A : baseA    
{
    public virtual void methodA()
    {
    }
}

public class B : baseB    
{
    public void method B()
    {
         var ClassA = new A();
    }

    /* Now Is there some sort of overide like */
    public override methodA()
    {
      //Do stuff
    }
}

And those classes do not inherit from each other, to make it more difficult. Now if this sort of construction is possible in c#?

Answer 1

No. You cannot override a class's behavior if you don't inherit from it.

The override modifier is required to extend or modify the abstract or virtual implementation of an inherited method, property, indexer, or event.

Class B must inherit from class A in order to do so.

public class A
{
    public virtual void methodA()
    {
    }
}

public class B : A
{
    public void methodB()
    {
        var ClassA = new A();
    }

    public override void methodA()
    {
        //Do stuff
    }
}

Check MSDN for more details:

An override method provides a new implementation of a member that is inherited from a base class. The method that is overridden by an override declaration is known as the overridden base method. The overridden base method must have the same signature as the override method