How to skip an immediate base class override function

Question

I have got the following class structure, and have plenty of classes like C derived from B, in some of the classes I dont want by B.OnShow() but I want A.OnShow() to be executed from C Any tricks?

abstract class A
{
   protected virtual void OnShow()
   {
        //some code
        base.OnShow();
   }
}

class B : A
{
    protected override void OnShow()
    {
      //some other code
      base.OnShow();
    }
}

class C : B
{
   protected override void OnShow()
   {
      //some other code
      base.OnShow();
   }
}

possible duplicate of [How to call a second-level base class method like base.base.GetHashCode()](http://stackoverflow.com/questions/1006530/how-to-call-a-second-level-base-class-method-like-base-base-gethashcode) — nawfal, May 02 '14 at 16:09

score 5 · Accepted Answer · answered Feb 27 '10 at 00:08

Don't have C extend from B, instead make a new class "X" that extends from A and has the parts that are currently in B that you want for both B and C and then have C and B extend from "X". Then B will just have the bits in it that you want for B specifically (a bit abstract, but I think that makes sense).

Generally speaking, if you are trying to skip a parent method then you are doing something wrong.

score 2 · Answer 2 · edited May 23 '17 at 10:32

2

Eric Lippert has already answered a very similar question and basically stated that it's not permitted in C#.

edited May 23 '17 at 10:32

Community

1
1

answered Feb 26 '10 at 23:57

Rob

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score 2 · Answer 3 · answered Feb 27 '10 at 00:04

It sounds like a design problem here. If C really is a B, it should probably do everything B needs to do in the OnShow. If not, you should probably be utilizing something other than direct inheritance, or something other than a single virtual function call.

If you really really wanted to, you could have:

abstract class A
{
    protected virtual void OnShow()
    {
        UniqueOnShowStuff();
        base.OnShow();
    }
    protected virtual void UniqueOnShowStuff()
    {
     //
    }
}

class B : A
{
    protected override void OnShow()
    {
        // Things all B's need to Show
        base.OnShow();
    }
    protected override void UniqueOnShowStuff()
    {
        // Things most B's might want to show but don't have to
    }
}

class C : B
{
    protected override void OnShow()
    {
        // Things all C's need to show
        base.OnShow();
    }
    protected override void UniqueOnShowStuff()
    {
        // override without a base call so you don't show B's things
    }
}

This is a horrible pattern though, and I wouldn't recommend it if you could come up with a better way to redesign the objects/functionality.

How to skip an immediate base class override function

3 Answers3