Can I prevent an inherited virtual method from being overridden in subclasses?

Question

I have some classes layed out like this

class A {     public virtual void Render()     {     } } class B : A {     public override void Render()     {         // Prepare the object for rendering         SpecialRender();         // Do some cleanup     }      protected virtual void SpecialRender()     {     } } class C : B {     protected override void SpecialRender()     {         // Do some cool stuff     } } 

Is it possible to prevent the C class from overriding the Render method, without breaking the following code?

A obj = new C(); obj.Render();       // calls B.Render -> c.SpecialRender 

Answer 1

You can seal individual methods to prevent them from being overridable:

public sealed override void Render() {     // Prepare the object for rendering             SpecialRender();     // Do some cleanup     } 

Answer 2

Yes, you can use the sealed keyword in the B class's implementation of Render:

class B : A {     public sealed override void Render()     {         // Prepare the object for rendering         SpecialRender();         // Do some cleanup     }      protected virtual void SpecialRender()     {     } }