Extend a method in the base class c#

Question

how do i extend a behaviour from the base class like this?

public class A  {
    protected virtual void foo () {
        Console.WriteLine("hi")
    }
}

public class B : A  {
    protected override void foo () {
        Console.WriteLine("hihi")
    }
}

a = new A();
a.foo() 

-> "hi"
-> "hihi"

When calling foo in the parent class i want to execute a behavior specific for that class while at the same time calling it in the child. Is it possible to do this with just accessing the parent?

Wont this call the base only? I only get "hihi" when doing this. — binbin, Apr 27 '17 at 21:47
`public class B : A { protected override void foo () { base.foo(); Console.WriteLine("hihi"); } }` — Gusman, Apr 27 '17 at 21:47
No, you cannot have a call to A automatically call a method in B. A, the parent, is unaware of its children. — PhilC, Apr 27 '17 at 21:50

score 3 · Accepted Answer · answered Apr 27 '17 at 21:46

3

You need to use the base keyword

base.myParentMethod();

Use that inside the overriden method if you want both actions to be performed.

answered Apr 27 '17 at 21:46

phadaphunk

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oh i didnt know it was a keyword, thats neat thanks. – binbin Apr 27 '17 at 21:50

Extend a method in the base class c#

1 Answers1