C
C#•2mo ago
T3M4CH

Get concrete generic type by Enum

Hello. Can someone explain how I can solve my problem. I have interface IContainerService<T> 
public interface IContainerService<T> : IContainerBase where T : Product
{
    void AddProduct(T product);
    T GetProduct(int id);
}
public interface IContainerService<T> : IContainerBase where T : Product
{
    void AddProduct(T product);
    T GetProduct(int id);
}
and Entity from Database with Type(Box, Pallet, BigBox etc.) and T(ProductCategory : Food, Animals, Clothes) 
public class Container
{
    public int Id { get; set; }
    public double MaxWeight { get; set; }
    public EContainerType Type { get; set; }
    public EProductType Category { get; set; }
}
public class Container
{
    public int Id { get; set; }
    public double MaxWeight { get; set; }
    public EContainerType Type { get; set; }
    public EProductType Category { get; set; }
}
And here's problem when I get my Container from DB Idk how to get concrete type and execute AddProduct method I've tried something like this but with no results cause IContainerBase doesn't contains AddProduct just general method. 
  public static IContainerBase CreateContainer(this Container container)
    {
        return (container.Type, container.Category) switch
        {
            (EContainerType.Box, EProductType.Animals) => new Box<Animals>(container.MaxWeight),

            (EContainerType.Box, EProductType.Food) => new Box<Food>(container.MaxWeight),

            (EContainerType.Box, EProductType.Clothes) => new Box<Clothes>(container.MaxWeight),

            (EContainerType.Pallet, EProductType.Animals) => new Pallet<Animals>(container.MaxWeight, 25.0),

            (EContainerType.Pallet, EProductType.Food) => new Pallet<Food>(container.MaxWeight, 25.0),

            (EContainerType.Pallet, EProductType.Clothes) => new Pallet<Clothes>(container.MaxWeight, 25.0),

            _ => throw new Exception("Bad container")
        };
    }
  public static IContainerBase CreateContainer(this Container container)
    {
        return (container.Type, container.Category) switch
        {
            (EContainerType.Box, EProductType.Animals) => new Box<Animals>(container.MaxWeight),

            (EContainerType.Box, EProductType.Food) => new Box<Food>(container.MaxWeight),

            (EContainerType.Box, EProductType.Clothes) => new Box<Clothes>(container.MaxWeight),

            (EContainerType.Pallet, EProductType.Animals) => new Pallet<Animals>(container.MaxWeight, 25.0),

            (EContainerType.Pallet, EProductType.Food) => new Pallet<Food>(container.MaxWeight, 25.0),

            (EContainerType.Pallet, EProductType.Clothes) => new Pallet<Clothes>(container.MaxWeight, 25.0),

            _ => throw new Exception("Bad container")
        };
    }
How can I get concrete type based by information from Enums? I want to get like method CreateContainer but with concreteType where I can call AddProduct and GetProduct method
1 Reply
Sossenbinder
Sossenbinder•2mo ago
Your problem is pretty much that you want to weave together a mostly compile time concept with generics with a runtime evaluation of your container, so your best bet is either to 1) Cast to a IContainerService<T> at runtime 2) Move shared logic into the shared base interface 3) Find a different approach for your factory which can properly deal with returning a proper IContainerService<T>

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