Question

I have two different classes deriving from one base class. They each have a collection deriving from another base class, but different derived class.

class MasterA : MasterBase<ClientA>
class MasterB : MasterBase<ClientB>

public class MasterBase<ClientClass> where ClientClass : ClientBase
{
    public List<ClientClass> Clients;
} 

Class ClientA : ClientBase
Class ClientB : ClientBase

Class ClientBase

What I want is to have a UserControl which works with the parent/child lists of both Master/Client of either type (A or B).

public class Test<MasterClass> where MasterClass : MasterBase<ClientBase>
{
    GenericRepository<MasterClass> repo = new GenericRepository<MasterClass>();
    MasterClass master = repo.GetAll;
    // do some changes to (base fields of) the master collection and its client collection !
    repo.SaveOrUpdate(master);
}

But…. I can’t instantiate that Test class..

var t = new Test<MasterA>();
>> There's no implicit reference conversation from MasterA to MasterBase<ClientBase>

So, is there some way I can modify the Test class to be able to do what I’ve indicated?
would really appreciate some hints.

Answer 1

Not knowing what constraints you were working under, originally posted this as a comment.

Would

public class Test<MasterClass,U> where MasterClass : MasterBase<U> where U: ClientBase

be a suitable change to your codebase? Obviously, this line would have to change also:

var t = new Test<MasterA,ClientA>();

The issue is that, just because there is an inheritance relationship between two classes, X and Y, that does not mean that the generic types G<X> and G<Y> have the same (or any) inheritance relationship. So MasterBase<ClientA> does not inherit from MasterBase<ClientBase>