class Program
    {
        static void Main(string[] args)
        {
            var input = Console.ReadLine();
            if (input = "help")
            {
                var output = "output content";
                Console.Write(output);
            }
        }

       
    }

------解决方案--------------------
改一下程序
class Program
   {
       static void Main(string[] args)
       {
          if(args.Length>2)
           var input = args[1];
           if (input = "help")
           {
               var output = "output content";
               Console.Write(output);
           }
       }

     
   }