SignalR Client Connection has been not established

Question

I created a SignalR Selfhosted application but can not access via browsers or Windows Phone (which is my client). I followed several tutorials and they pretty much say the same thing, I believe that the error is on my network configuration also notice that when you run the project, the IIS does not fire (not sure if it is also required).

SignalRServer:

class Program : Hub
    {
        private static HubConnection Connection { get; set; }
        private static IHubProxy HubProxy { get; set; }

        const string Url = "http://*:8080";

        static void Main(string[] args)
        {
            // This will *ONLY* bind to localhost, if you want to bind to all addresses
            // use http://*:8080 to bind to all addresses. 
            // See http://msdn.microsoft.com/en-us/library/system.net.httplistener.aspx 
            // for more information.

            using (WebApp.Start(Url))
            {
                Console.WriteLine("Servidor rodando em {0}", Url);
                Console.ReadLine();
            }
        }

        private static void Connection_Closed()
        {
            Connection = null;
        }
    }

    class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            app.UseCors(CorsOptions.AllowAll);
            app.MapSignalR();
        }
    }

The error is:

The connection has not been established.

My Client class:

public class SignalRService : PhoneApplicationPage
    {
        public String UserName { get; set; }

        public IHubProxy HubProxy { get; set; }

        private const string ServerURI = "http://localhost:8080";

        public HubConnection Connection { get; set; }

        public SignalRService()
        {
            UserName = "Luizaooo";

            ConnectAsync();
        }

        public void ObterAtualizacoesProdutos()
        {
            ProdutoService produtoService = new ProdutoService();
            var dataHora = produtoService.ObterDataHoraUltimaAtualizacao();
            HubProxy.Invoke("ObterAtualizacoes", dataHora);
            MessageBox.Show("passou");
        }

        private async void ConnectAsync()
        {
            Connection = new HubConnection(ServerURI);
            Connection.Closed += Connection_Closed;
            HubProxy = Connection.CreateHubProxy("ProdutoHub");

            HubProxy.On<List<Produto>>("AtualizarProdutos", (ListaDeProdutos) =>
                this.Dispatcher.BeginInvoke(() =>
                {
                    var a = ListaDeProdutos;
                }));

            try
            {
                await Connection.Start();
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
                return;
            }
        }

        private void Connection_Closed()
        {
            Connection = null;
        }
    }

Answer 1

Getting the Startup class to be recognized correctly can be tricky, especially in self-host scenarios.

For your code, first check if the Configuration method is actually running. If it isn't, add

[assembly: OwinStartup(typeof(Program.Startup))]

above the namespace decleration as described here: Owin Startup Detection

You can bypass this problem entirely by using the overload of WebApp.Start that takes a predicate:

 WebApp.Start(url, new Action<IAppBuilder>((app) =>
 {
     app.UseCors(CorsOptions.AllowAll);
     app.MapSignalR();
 }));

Either way, test your connection by navigating to http://localhost:8080/signalr/hubs . If that shows you a signalR javascript file, you will know that your service is up and running