Initialize generic object from a System.Type

Question

I need to create a generic type, but I do not know the type at compile time. I would like to do this:

Type t = typeof(whatever);
var list = new List<t>

this won't compile, because t is not a valid type. But it does know all about a valid type. Is there a way to dynamically create the generic list from a System.Type like this? I may need reflection, and that's ok, I am just a bit lost here.

Answer 1

Like this:

Type t;
Type genericListType = typeof(List<>).MakeGenericType(t);
object list = Activator.CreateInstance(genericListType);

Note that you can only assign it to a variable of type object. (Although you can cast to to the non-generic IList interface)

To use the list variable, you'll probably need reflection.