//CREDIT AND THANKS TO: learn.microsoft.com  
      static void Main()
        {
            try
            {
                Parallel.Invoke(
                    LaPrimaAzione,	
                    () =>			
                    {
                        Console.WriteLine("Method=2 - Thread={0}", Thread.CurrentThread.ManagedThreadId);
                    },
                    delegate()	
                    {
                        Console.WriteLine("Method=3 - Thread={0}", Thread.CurrentThread.ManagedThreadId);
                    }
                );
            }
            catch (AggregateException e)
            {
                Console.WriteLine("ERROR: {0} \n", e.InnerException.ToString());
            }
        }

        static void LaPrimaAzione()
        {
            Console.WriteLine("Method=1 - Thread={0}", Thread.CurrentThread.ManagedThreadId);
        }