Question

I need to validate an object to see whether it is null, a value type, or IEnumerable<T> where T is a value type. So far I have:

if ((obj == null) ||     (obj .GetType().IsValueType)) {     valid = true; } else if (obj.GetType().IsSubclassOf(typeof(IEnumerable<>))) {      // TODO: check whether the generic parameter is a value type. } 

So I’ve found that the object is null, a value type, or IEnumerable<T> for some T; how do I check whether that T is a value type?

Answer 1

(edit – added value type bits)

You need to check all the interfaces it implements (note it could in theory implement IEnumerable<T> for multiple T):

foreach (Type interfaceType in obj.GetType().GetInterfaces()) {     if (interfaceType.IsGenericType         && interfaceType.GetGenericTypeDefinition() == typeof(IEnumerable<>))     {         Type itemType = interfaceType.GetGenericArguments()[0];         if(!itemType.IsValueType) continue;         Console.WriteLine('IEnumerable-of-' + itemType.FullName);     } }