Polymorphism Through Extension Methods?

Question

I have a class library which contain some base classes and others that are derived from them. In this class library, I\'m taking advantage of polymorphism to do what I want it t

Answer 1

I was looking for the same thing just now.

You could add one more method to your extension class like this:

public static void DoSomething(this Base myObj, Object dependency)
{       
    if(myObj.IsSubclassOf(Base))
    {
      // A derived class, call appropriate extension method.  
      DoSomething(myObj as dynamic, dependency);
    }
    else
    {
        // The object is Base class so handle it.
    }
} 

You don't need the if/else check if the base class is abstract (or never used in the wild):

public static void DoSomething(this Base myObj, Object dependency)
{ 
    DoSomething(myObj as dynamic, dependency);
}

[Edit] Actually this won't work in your case as you don't implement support for all derived objects (so could still get infinite recursion). I guess you could pass something to check for recursion but the given answer is the simplest. I'll leave this here as it might spark more ideas.