How to search for users in Active Directory with C#

Last time I wrote about how you can reach the Active Directory search dialog in Windows 7. Today I’ll show you how to search comfortable for users in the Active Directory by using C#. The emphasis is on comfort, because there are quite a few articles on the subject in general, on the internet.
However, most of the shown methods/solutions are build exclusively around System.DirectoryServices.ActiveDirectory and the DirectorySearcher. But ever since .NET 3.5 it is also possible to search in the Active Directory much easier.
But let us come to the point. In the following example, I mostly use methods from the System.DirectoryServices.AccountManagement namespace. And here’s how:

//Create a shortcut to the appropriate Windows domain
PrincipalContext domainContext = new PrincipalContext(ContextType.Domain,