Get all classes from a namespace that implements certain interface using System.Reflection

Question

I have multiple classes in a namespace implementing certain interface, and I want to make a list of all classes, that match the same interface.

Is there a way to reach that using System.Reflection?

public interface A
{}
public class AB : A
{}
public class AC : A
{}
public class AD : A
{}

List<A> classList = { AB, AC, AD};

Thanks.

how is is this duplicate if he asks about the namespaces and the question is answering about assemblies? — cikatomo, Feb 13 '22 at 15:17

score 1 · Answer 1 · answered Dec 07 '13 at 11:18

try this

            var interfaceType = typeof(A);
            var classes = AppDomain.CurrentDomain.GetAssemblies()
                .SelectMany(s => s.GetTypes())
                .Where(interfaceType.IsAssignableFrom).ToList();
            classes.Remove(typeof(A));

score 0 · Answer 2 · answered Dec 07 '13 at 11:12

Yes. You will need to know which assembly the types are in. Then get the types from that assembly, and find the ones that implement your interface.

Assembly a = typeof(A).Assembly;
var list = a.GetTypes().Where(type => type != typeof(A) && typeof(A).IsAssignableFrom(type)).ToList();

score -1 · Answer 3 · answered Dec 07 '13 at 11:15

Yes, see Type.implementsInterface for more information. http://msdn.microsoft.com/en-us/library/bb383789(v=vs.100).aspx

You can also use typeof(IWhateverable).IsAssignableFrom(myType)

More information from here: http://www.hanselman.com/blog/DoesATypeImplementAnInterface.aspx

Get all classes from a namespace that implements certain interface using System.Reflection

3 Answers3