In the C# programming language, the UserName property of the Environment class is used to find the active user name in the current operating system.

An example of this usage is given below.

namespace ConsoleApplicationTest
{
    class Program {

        static void Main(string[] args) {

            string uName = System.Environment.UserName;

            Console.WriteLine(uName);
            Console.ReadLine();

        }
    }
}