Is it possible to get all names from a role? NetSqlAzMan

Question

I need to get all the names from a NetSqlAzMan role in c#. It is possible? And how? I am working on an ASP.NET Core 1 application.

In particular, I need to get the member name, that was manually added to the role, having the name of the role (DSPCC).

Thanks in advance!