using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

​

namespace DataAccess

{

    public class Categories : BaseService<Database.Categories>

    {

    }

​

    public class Users : BaseService<Database.Users>

    {

    }

}

​

namespace Models

{

    public class Categories

    {

        public int Id {get;set;}

        public string Name {get;set;}

    }

    public class Users

    {

        public int Id {get;set;}

        public string Name {get;set;}

        public string Email {get;set;}

    }

}

​

namespace Database

{

    public class Categories

    {

        public int Id{get;set;}

        public string Name {get;set;}

    }

    public class Users

    {

        public int Id{get;set;}

        public string Name {get;set;}

        public string Email {get;set;}

    }

}

​

public interface IBaseService<TObject> where TObject : class

{

    ICollection<TObject> GetAll();

}

​

public class BaseService<TObject> : IBaseService<TObject> 

    where TObject : class

{

    public ICollection<TObject> GetAll()

    {

        throw new NotImplementedException();

    }

}

​

public static class DA

{

    public static DataAccess.Categories Categories => new DataAccess.Categories();

    public static DataAccess.Users Users => new DataAccess.Users();

}

​

public static class DA<TDBModel>

    where TDBModel : class

{

    public static BaseService<TDBModel> Base => new BaseService<TDBModel>();

}

​

namespace BusinessLogic

{

    public class Categories

    {

    }

    public class Users

    {

    }   

}

​

public static class BL

{

    public static BusinessLogic.Categories Categories => new BusinessLogic.Categories();    

    public static BusinessLogic.Users Users => new BusinessLogic.Users();   

}

​

public class BL<TModel>

{

    // This is what i want to make dynamic.

    // how do i create a return type that i can use in DA<>..

    private Type testDetermineDatabaseModel()

    {

        switch(typeof(TModel).Name){

            case "Categories":

                return typeof(Database.Categories);

            case "Users":

                return typeof(Database.Users);

        }

        return null;

    }

    public ICollection<TModel> testGetAll() 

    {

        var databaseModel = testDetermineDatabaseModel();

        // return DA<databaseModel>().Base.GetAll();

        return new List<TModel>();

    }

    // NEW

    // I have constructed the following.

    private IBaseService<dynamic>  baseService;

    public dynamic DetermineDatabaseModel()

    {

        switch (typeof(TModel).Name)

        {

            case "Categories":

                return new BaseService<Database.Categories>();

            case "Users":

                return new BaseService<Database.Users>();

            default:

                return null;

        }

    }

    private IBaseService<TDbModel> GetBase<TDbModel>() where TDbModel : class

    {

        return new BaseService<TDbModel>();

    }

    public ICollection<TModel> GetAll()

    {

        ICollection<TModel> returnValue = new List<TModel>();

        // This works!!!

        foreach (var item in GetBase<Database.Categories>().GetAll())

        {

            returnValue.Add((TModel)(object)item);

        }

        baseService = DetermineDatabaseModel();

        // This doesn't!!! It's the same thing!! :(

        foreach (var item in baseService.GetAll())

        {

            returnValue.Add((TModel)(object)item);

        }

        return returnValue;

    }

}

​

​

​

​