How to compare types when using generics?

Question

I am trying to get the type of an object at runtime. In particular, I need to know two things: whether it implements ICollection or IDto. Currently, my only solution I could find is the following:

   private static bool IsACollection(PropertyDescriptor descriptor)
    {
        bool isCollection = false;

        foreach (Type type in descriptor.PropertyType.GetInterfaces())
        {
            if (type.IsGenericType)
            {
                if (type.GetGenericTypeDefinition() == typeof(ICollection<>))
                {
                    isCollection = true;
                    break;
                }
            }
            else
            {
                if (type == typeof(ICollection))
                {
                    isCollection = true;
                    break;
                }
            }
        }


        return isCollection;
    }

    private static bool IsADto(PropertyDescriptor descriptor)
    {
        bool isDto = false;

        foreach (Type type in descriptor.PropertyType.GetInterfaces())
        {
            if (type == typeof(IDto))
            {
                isDto = true;
                break;
            }
        }          
        return isDto;
    }

However, I am convinced that there must be a better way than this. I tried comparing in the usual way, for example:

if(descriptor.PropertyType == typeof(ICollection<>))

However, this does not work when using reflection, when reflection is not used, it works fine.

I do not want to iterate over the interfaces for each field of my object. Can someone shed light on another method to do this? Yes, I optimize prematurely, but it looks ugly, so please humor me.

Cautions:

• , IList < > ArrayList, ICollection ICollection < > . , IsGenericType if, , ICollection < > .

!

Answer 1

:

type == typeof(ICollection)

, ICollection. , :

public ICollection<int> x { get; set; }

:

public List<int> x { get; set; }

, ICollection, - Type.IsAssignableFrom:

typeof(ICollection).IsAssignableFrom(type)

:

typeof(ICollection<>).IsAssignableFrom(type.GetGenericTypeDefinition())

Answer 2

type.IsAssignable ?

EDIT: , Type.IsAssignableFrom