How to call method of instance of generic type when it's type argument is unknown?

Question

This seems like basic problem, but I'm struggling with it (maybe because of tiredness).

E.g. - if i create instance of repository like this =>

var repositoryType = typeof(Repository<>).MakeGenericType(entityType);
// repository type==object :(
var repository = ServiceLocator.Current.GetInstance(repositoryType); 

What's the best way to call repository.All() method? Is reflection the only way?

Answer 1

In .Net 3.5, it is not possible to do this without reflection or worse.

Answer 2

It depends whether Repository<> exposes some non-generic interface (like ITable compared to Table<T> in LINQ-to-SQL). If not, you have to use reflection. If it does, then cast to the non-generic interface:

IRepository repository = (IRepository)ServiceLocator
    .Current.GetInstance(repositoryType); 
IList data = repository.All();

In 4.0, you could also consider dynamic:

dynamic repository = ServiceLocator.Current.GetInstance(repositoryType); 
IList data = repository.All();