null-cast

Evaluate null cast with reflection?

Given a null cast: var result = MyMethod( (Foo) null ); Is it possible to use this extra information inside the method with reflection? EDIT: The method's signature is something like: object MyMethod( params object[] args ) { // here I would like to see that args[0] is (was) of type Foo } ...

Which is preferred: new Nullable<int> or (int?)null ?

Which way is preferred in expressions like this: int? Id { get { int i; return Int32.TryParse(Request["id"], out i) ? i : (int?)null; } } is it better to cast on null or create a new Nullable<T> ? ...