Setup:
- SignalRServer console app: Microsoft.AspNet.SignalR.SelfHost v2.0.3
- SignalRClient console app: Microsoft.AspNet.SignalR.Client v2.0.3
- .NET 4.5.1
I do the following:
- Hit enter on client, a message is received at server and on client again
- Dispose the server by hitting any key in the server console
- Restart the server by hitting any key in the server console
- Client is reconnected
- Hit enter on client, message is received at server, but never reaches the client again
I expect the message to be received at the client again. I suspect it has something to do with the self-hosting, since I've tried to run the client against same hub in a web application running IIS with success.
Any ideas?
Update: if the server console process is killed and restarted, it is able to reconnect AND retrieve messages again.
Server code
using System;
using System.Threading.Tasks;
using Microsoft.AspNet.SignalR;
using Microsoft.Owin.Hosting;
using Owin;
namespace SignalRServer
{
internal class Program
{
private static void Main(string[] args)
{
const string url = "http://localhost:8081";
while (true)
{
using (WebApp.Start<Startup>(url))
{
Console.WriteLine("Server running on {0}. Hit any key to stop.", url);
Console.ReadLine();
}
Console.WriteLine("Server stopped");
Console.WriteLine("Hit any key to restart, Esc to exit");
ConsoleKeyInfo ki = Console.ReadKey(true);
if (ki.Key == ConsoleKey.Escape)
return;
}
}
}
public class Startup
{
public void Configuration(IAppBuilder app)
{
app.MapSignalR();
}
}
public class AuthenticationHub : Hub
{
public void BroadcastMessageToAll(string message)
{
Clients.All.sendMessageToClient(message);
Console.WriteLine("sendMessageToClient: " + message);
}
public override Task OnConnected()
{
Console.WriteLine("OnConnected " + Context.ConnectionId);
return base.OnConnected();
}
public override Task OnReconnected()
{
Console.WriteLine("OnReconnected " + Context.ConnectionId);
return base.OnReconnected();
}
public override Task OnDisconnected()
{
Console.WriteLine("OnDisconnected " + Context.ConnectionId);
return base.OnReconnected();
}
}
}
Client code
using System;
using Microsoft.AspNet.SignalR.Client;
namespace SignalRClient
{
class Program
{
static void Main(string[] args)
{
while (true)
{
var hubConnection = new HubConnection("http://localhost:8081/signalr/hubs");
hubConnection.Closed += () => Console.WriteLine("Closed");
hubConnection.StateChanged += e => Console.WriteLine("StateChanged: " + e.OldState + " " + e.NewState);
var hubProxy = hubConnection.CreateHubProxy("AuthenticationHub");
hubProxy.On<string>("sendMessageToClient",
info => Console.WriteLine("sendMessageToClient received: " + info));
hubConnection.Start();
Console.WriteLine("Client started - hit Enter to send a message - ESC to stop");
Console.ReadKey();
while (true)
{
var keyInfo = Console.ReadKey(true);
if (keyInfo.Key == ConsoleKey.Escape)
break;
var message = "Console client : " + DateTime.Now.ToString("HH:mm:ss-fff");
hubProxy.Invoke("BroadcastMessageToAll", message);
Console.WriteLine("Client sent BroadcastMessageToAll: " + message);
}
Console.WriteLine("Client stopping");
hubConnection.Stop();
Console.WriteLine("Client stopped - enter any key start again");
Console.ReadLine();
}
}
}
}
The SignalR team pointed me to the solution: By default SignalR uses GlobalHost, which is a singleton resolver. When disposed, it will never come back.
When creating the configuration for the hub, you should pass inn a new dependency resolver:
public class Startup
{
public void Configuration(IAppBuilder app)
{
var hubConfiguration = new HubConfiguration {Resolver = new DefaultDependencyResolver()};
app.MapSignalR(hubConfiguration);
}
}
Stian's answer is great. But if you need to use static methods defined in GlobalHost, you need to assign the Dependency resolver to GlobalHost.
The following works for me:
public void Configuration(IAppBuilder app)
{
.... Other configurations ....
GlobalHost.DependencyResolver = new DefaultDependencyResolver();
app.MapSignalR();
}
I defined the hub context this way:
public sealed class RemoteAdminHub : Hub
{
#region Properties
/// <summary>
/// Gets the SignalR Hub context.
/// </summary>
public static IHubContext HubContext
{
get
{
return GlobalHost.ConnectionManager.GetHubContext<RemoteAdminHub>();
}
}
#endregion
}
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