Implicit en conversions to c # generic classes

I have an application that is structured as a service layer that uses the repository layer to persist. I'm trying to create a generic controller class to reuse shared behavior, but I'm having trouble trying to set the generic options. The following code:

public class BusinessEntity
{ }

public class Person : BusinessEntity
{ }

public interface IRepository<T> where T : BusinessEntity
{ }

public interface IService<T, R>
    where T : BusinessEntity
    where R : IRepository<T>
{ }

public partial interface IPersonRepository : IRepository<Person>
{ }

public interface IPersonService : IService<Person, IPersonRepository>
{ }

public abstract class BaseController<X, Y>
    where X : BusinessEntity
    where Y : IService<X, IRepository<X>>
{ }

public class PersonController : BaseController<Person, IPersonService>
{ }

      

cannot compile with

A type ConsoleApplication.IPersonService

cannot be used as a type parameter Y

in a generic type or method ConsoleApplication.BaseController<X,Y>

. There is no implicit conversion of references from ConsoleApplication.IPersonService

toConsoleApplication.IService<ConsoleApplication.Person,ConsoleApplication.IRepository<ConsoleApplication.Person>>

it works

public interface IPersonService : IService<Person, IRepository<Person>>

      

but I am losing my custom repository

Is there a way to make the compiler implemented IPersonRepository

- is this IRepository<Person>

?

+3


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2 answers


public class BusinessEntity
{ }

public class Person : BusinessEntity
{ }

public interface IRepository<T> where T : BusinessEntity
{ }

public interface IService<T, R>
    where T : BusinessEntity
    where R : IRepository<T>
{ }

public partial interface IPersonRepository : IRepository<Person>
{ }

public interface IPersonService : IService<Person, IPersonRepository>
{ }

public abstract class BaseController<X, Y, Z>
    where X : BusinessEntity
    where Y : IService<X, Z>
    where Z : IRepository<X>
{ }

public class PersonController : BaseController<Person, IPersonService, IPersonRepository>
{ } 

      

To submit your comment:

IPersonService can extend the base service class to add custom tools such as FindPersonsUnderAge (). This requires a dedicated repository. In fact, LINQ avoids a lot of custom repository codes, but sometimes they are required.



Can't IPersonService do this without requiring the repository type to be a type parameter? For example:

public interface IService<T> where T : BusinessEntity { } 

public interface IPersonService : IService<Person>
{
    IEnumerable<Person> FindPersonsByAge(double minAge, double maxAge);
}

public class Service<T, R> : IService<T>
    where T : BusinessEntity 
    where R : IRepository<T> 
{ }

public class PersonService : Service<Person, IPersonRepository>, IPersonService
{ }

      

+4


source


Thanks sll for pointing me in the right direction

public interface IService<T, out R>
    where T : BusinessEntity
    where R : IRepository<T>
{ }

      



does the trick

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