Question

typeof(Nullable<>)

public static bool IsNullableType(Type t)
        {
            return t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Nullable<>);
        }

I was using this to check whether Lambda Expressioin parameters are nullable.

Answer 1

There’s no need to do this yourself – you can just use Nullable.GetUnderlyingType which returns Nothing/null if the type you pass it isn’t nullable:

Public Shared Function IsNullable(t as Type) As Boolean
   Return Nullable.GetUnderlyingType(t) IsNot Nothing
End Function

(But if you really need an open generic type, then GetType(Nullable(Of)) will work. If you need multiple type parameters, just comma-separate them, e.g. GetType(Dictionary(Of ,)).)