Partial Method Inside Abstract Class (C#)

Question

I'm creating an abstract class that can be inherited in a partial class of a LINQ to SQL class. The LINQ to SQL class contains a bunch of built-in partial methods. Is there a way that I can implement one or more of the partial methods in the abstract class? I know that partial methods can only be contained within partial classes or structs. I'm sure there's got to be another way to do it.

Here's more detail:

• I may have a database table called News. If I create a LINQ to SQL dbml file containing this table, the auto-generated code generates a partial class for News.
• This partial class contains several partial methods.
• I have a class that I'm building that contains several methods that I'd like to use across all my LINQ to SQL classes.
• One of these methods is a partial method added to each LINQ to SQL class. I have a common body to use for this method. Rather than adding this method to each partial class, I'm looking for a way to create it once and inherit it with my base class inheritance.

Hope that helps explain more.

Answer 1

I think I understand what you want to do, but if not, let me know. You can make your abstract base class partial and pull the implementation you want up into that class. Alternatively, you could take your abstract class and encapsulate the functionality you want your child classes to have access to.

Answer 2

Partial methods are not usable over inheritance. You could add regular methods to the abstract base class, but they won't automatically "pair" with the partial method declarations. So: no. You can, of course, simply have the partial method implementation call into the base-class.

Note also that if the common code relates to things like audit (who/when), you can also do this by overriding the DataContext's SubmitChanges method, and calling GetChangeSet:

    public override void SubmitChanges(ConflictMode failureMode)
    {
        ChangeSet delta = GetChangeSet();
        //... use delta.Updates, delta.Inserts and delta.Deletes
        base.SubmitChanges(failureMode);
    }

Finally, note that you can also specify a common base-class for all your entities in the dbml (like so); you don't have to do it by hand in each partial class.