C# Reflected Property Type

Question

I am using reflection to get the values out of an anonymous type:

object value = property.GetValue(item, null);

when the underlying value is a nullable type (T?), how can I get the underlying type when the value is null?

Given

int? i = null;

type = FunctionX(i);
type == typeof(int); // true

Looking for FunctionX(). Hope this makes sense. Thanks.

Answer 1

You can do something like this:

if(type.IsgenericType)
{
   Type genericType = type.GetGenericArguments()[0];
}

EDIT: For general purpose use:

public Type GetTypeOrUnderlyingType(object o)
{
   Type type = o.GetType();
   if(!type.IsGenericType){return type;}
   return type.GetGenericArguments()[0];
}

usage:

int? i = null;

type = GetTypeOrUnderlyingType(i);
type == typeof(int); //true

This will work for any generic type, not just Nullable.

Answer 2

from what I understand on http://blogs.msdn.com/haibo_luo/archive/2005/08/23/455241.aspx you will just get a Nullable version of the type returned.

Answer 3

If you know that is Nullable<T>, you can use the static helper GetUnderlyingType(Type) in Nullable.

int? i = null;

type = Nullable.GetUnderlyingType(i.GetType());
type == typeof(int); // true