MT4 Connecting

MT4 contains server details (address and port) in  *.srv files. For simple application is enough to get just primary server as shown below.    

using System;
using TradingAPI.MT4Server;
 
namespace Help
{
  class Program
  {
    static void Main(string[] args)
    {
      new Program().Run();
    }
 
    void Run()
    {
      try
      {
        MainServer srv = QuoteClient.LoadSrv(@"GerchikCo-Demo.srv");
        QuoteClient qc = new QuoteClient(67611, "wx1yhpn", srv.Host, srv.Port);
        Console.WriteLine("Connecting...");
        qc.Connect();
        Console.WriteLine("Connected to server");
        Console.WriteLine("Press any key...");
        Console.ReadKey();
        qc.Disconnect();
 
      }
      catch (Exception ex)
      {
        Console.WriteLine(ex.Message);
        Console.WriteLine("Press any key...");
        Console.ReadKey();
      }
    }
  }
}

In real applications you need to get also slave servers and connect to them if primary server not available.

void Run()
{
   try
   {
      Server[] slaves;
      MainServer primary = QuoteClient.LoadSrv(@"GerchikCo-Demo.srv", out slaves);
      QuoteClient qc = Connect(primary, slaves, 67611, "wx1yhpn");
      Console.WriteLine("Connected to server");
   }
   catch (Exception ex)
   {
      Console.WriteLine(ex.Message);
   }
   Console.WriteLine("Press any key...");
   Console.ReadKey();
}
 
QuoteClient Connect(MainServer primary, Server[] slaves, uint user, string password)
{
   Console.WriteLine("Connecting...");
   QuoteClient qc = new QuoteClient(user, password, primary.Host, primary.Port);
   try
   {
      qc.Connect();
      return qc;
   }
   catch (Exception)
   {
      Console.WriteLine("Cannot connect to main server");
      return ConnectSlaves(slaves, user, password);
   }
}
 
QuoteClient ConnectSlaves(Server[] slaves, uint user, string password)
{
   Console.WriteLine("Connecting to slaves...");
   foreach (var server in slaves)
   {
      QuoteClient qc = new QuoteClient(user, password, server.Host, server.Port);
      try
      {
         qc.Connect();
         return qc;
      }
      catch (Exception)
      {
      }
   }
   throw new Exception("Cannot connect to slaves");
}

Broker could periodically change .srv file, if you want to get such updates use PathForSavingSrv field. If you set this field before Connect() method it would be updated during connection.