override static methods

Question

Very simple question.  Why is it impossible to override static method in C#?

I would like to be able to do the following:

public interface IParent

{

object execute(object dataObject);

}

class Child : IParent

{

public static override object execute(object dataObject)

{

return obj;

}

}

 

 

What should I use instead?

Thx

Answer 1

No you cannot override a static method.

from http://msdn.microsoft.com/library/default.asp?url=/library/en-us/csref/html/vclrfOverridePG.asp

You cannot override a non-virtual or static method. The overridden base method must be virtual, abstract, or override.

 

I am not quite following what it is you are trying to do here well enough to tell you how you should do it. Could you give a bit more concrete of an example because you also have the static method seemingly implementing an interface method.

Answer 2

I have small business logic units that I call Transaction Scripts.  These are nothing but classes with only one static method called execute.  That method takes an object as a parameter and returns an object.

I would like to create a "Pattern" forcing other programmers who want to create a new Transaction Script to do it in a correct way.

Then, for every new Transaction Script created, if that "Pattern" is extended, I will be sure that the new class has a static execute method with the right signature.

Answer 3

Static method are used when you need to access a method without the need to create an object of the class. So it does not really belong the that class.

Here is a good thread with some solution:

http://groups.google.com/group/microsoft.public.dotnet.languages.csharp/browse_thread/thread/e0e6de961b8d4ca9/880898da81f4fd62?lnk=st&rnum=1&hl=en#880898da81f4fd62.

Answer 4

It is interesting that you have chosen this name; it also happens to be an official pattern name for a very similar concept http://www.martinfowler.com/eaaCatalog/transactionScript.html:) One major difference you will see in the pattern is that instead of having a single object represent a single operation; the object will encapsulate multiple related functionalities.

As the_lotus points out the only difference between the static method and the instance method would be the need to instantiate the object. I would generally lean towards just instantiating the object.

Greg