CODEWITHSUNDEEP
c#entity-frameworkinheritanceextension-methods
k4st0r42
k4st0r42

Reputation: 1252

Extension methods and inheritance

At first, I have an extension method for DbContext class to save with logs :

public static int SaveChangesWithLogging(this DbContext context, NLog.Logger logger)
{
    //logging
    //[...]

    return context.SaveChanges();
}

Then, I have a class which inherit from dbcontext and where I override SaveChanges()

public class ChildDbContext : DbContext
{
    public override int SaveChanges()
    {
        //other stuff
        //[...]

        //doesn't work, no definition for SaveChangesWithLogging (extension method not found, why ?)
        return base.SaveChangesWithLogging();


        //doesn't work, loop on SaveChanges by extension method and stack overflow as a result
        return base.SaveChangesWithLogging();
    }
}

I want to call the SaveChanges() of base DbContext class, but it call SaveChanges() of ChildDbContext or I have a loop and a stack overflow...

What is the good solution ?

Upvotes: 1

Views: 784

Answers (2)

k4st0r42
k4st0r42

Reputation: 1252

Finally, I use a wrapper for my dbcontext.

Upvotes: 0

D Stanley
D Stanley

Reputation: 152556

The extension method is hiding the real problem is that you're trying to call an overridden method from the outside, which is not possible. Since the actual object is a ChildDbContext, the overridden method will be called by SaveChangesWithLogging. There's not a way to call the "base" method from within SaveChangesWithLogging - even if you cast it before of after the method.

I suggest rearranging your call hierarchy so that the base method can be called from the derived method, or using non-virtual methods so that the base method can be called directly.

Upvotes: 1

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