static void Main(string[] args) { RpcServer rs = new RpcServer(new mpSerializer()); rs.start(); var str = Console.ReadLine(); while (str != "ccc") { str = Console.ReadLine(); var fs = rs.getAllSessions().FirstOrDefault(); if (fs == null) { Console.WriteLine("fs is null"); continue; } var xx = fs.InvokeApi <string>("GetVersion").GetAwaiter().GetResult(); Console.WriteLine(xx); } }