Determine current domain controller programmatically

.net, active-directory, c#, domaincontroller, domainservices

Solution

(requires System.DirectoryServices.AccountManagement.dll):

using (var context = new System.DirectoryServices.AccountManagement.PrincipalContext(ContextType.Domain))
{
    string server = context.ConnectedServer; // "pdc.examle.com"
    string[] splitted = server.Split('.'); // { "pdc", "example", "com" }
    IEnumerable<string> formatted = splitted.Select(s => String.Format("DC={0}", s));// { "DC=pdc", "DC=example", "DC=com" }
    string joined = String.Join(",", formatted); // "DC=pdc,DC=example,DC=com"

    // or just in one string

    string pdc = String.Join(",", context.ConnectedServer.Split('.').Select(s => String.Format("DC={0}", s)));
}

Problem

I need to query current domain controller, probably primary to change user password. (P)DC name should be fully qualified, i.e. `DC=pdc,DC=example,DC=com` (how to properly name such notation?) How can it be done using C#?

Original source