How to convert dictionary to NSDictionary ios C#

Question

I have a dictionary of type Dictionary(Enum,CustomClass)

since i need to post notification and pass the dictionary values i need to use NSDictionary instead of dictionary of C#. How do i convert this? if i use the following solution, it gives me an error Xamarin.iOS, convert Dictionary to NSDictionary

Cannot convert enumtype to NSObject NSNotificationCenter.DefaultCenter.PostNotificationName(notificationame,null,nsdictionary object);