.net abstract override quirk

Question

Suppose I have the following C # classes:

abstract class a
{
    protected abstract void SomeMethod();
}

abstract class b : a
{
    protected abstract override void SomeMethod();
}

class c : b
{
    protected override void SomeMethod()
    {

    }
}

Is there any point in overriding a method in b when it can be written just as easily:

abstract class b : a
{
}

What would be the “preferred” way to overlay b? And if it makes no sense to redefine an abstract method or property, why is this allowed?

Answer 1

One of the reasons you might want to do this: it shows intent. It explains that yes, you know that this method is abstract in the base class. I know this, and I still want it to be abstract here.

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Answer 2

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1:

public abstract class A
{
    public abstract void Foo();
    public abstract void Goo();
}

public abstract class B : A
{

    public abstract override void Foo();

    public override void Goo()
    {
        Console.WriteLine("Only wanted to implement goo");
    }
}

public class C : B
{

    public override void Foo()
    {
        Console.WriteLine("Only wanted to implement foo");
    }
}

2:

public abstract class A
{
    public virtual void Foo()
    {
        Console.WriteLine("A Foo");
    }
    public abstract void Goo();
}

public abstract class B : A
{

    public abstract override void Foo();

    public override void Goo()
    {
        Console.WriteLine("Only wanted to implement goo");
    }
}

public class C : B
{

    public override void Foo()
    {
        Console.WriteLine("Forced to implement foo");
    }
}

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Answer 3

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Answer 4

:

override , . , .

abstract class b : a
{
  [SomeAttribute]  
  protected abstract override void SomeMethod();
}

Answer 5

You do not need to override SomeMethod () in b. An abstract class declares that it can have undefined / abstract methods. When you extend one abstract class to another, it implicitly inherits any abstract methods from the parent.