I have looked around at some of the Similar questions and didn't figure this problem out. I have a simple Hub in my .NET core Web API project. Here is the Hub:
public class NotificationHub : Hub<INotificationClient>
{
public async Task SendMessage(string user, string msg)
{
await Clients.All.ReceiveMessage(user, msg);
}
public Task SendMessageToCaller(string msg)
{
return Clients.Caller.ReceiveMessage(msg);
}
public Task SendMessageToPartner(string user, string msg)
{
return Clients.Client(user).ReceiveMessageToPartner(msg);
}
}
Here is the Interface:
public interface INotificationClient
{
Task ReceiveMessage(string user, string msg);
Task ReceiveMessage(string msg);
Task ReceiveMessageToPartner( string msg);
}
Here is the code from the controller:
[Route("[controller]")]
[ApiController]
public class NotificationsController : ControllerBase
{
private IHubContext<NotificationHub> _hub;
public NotificationsController(IHubContext<NotificationHub> hub)
{
_hub = hub;
}
[HttpGet]
public async Task<IActionResult> Get()
{
var msg = new NotificationData { ClientId = "12345", Notification = "Somone just connected" };
await _hub.Clients.All.SendAsync("Notification", msg);
return Ok(new { Message = "Request complete" });
}
}
Lastly here is the console client code:
Console.WriteLine("Press a key to start listening");
Console.ReadKey();
Console.WriteLine("Client Listening!");
var connection = new HubConnectionBuilder()
.WithUrl("http://localhost:61514/notifications")
.Build();
connection.On<NotificationData>("Notification", (notificationData) =>
Console.WriteLine($"Somebody connected: {notificationData.ClientId}"));
connection.StartAsync().GetAwaiter().GetResult();
Console.WriteLine("Listening. Press a key to quit");
Console.ReadKey();
Here is the startup of the web app with the mappings:
public void ConfigureServices(IServiceCollection services)
{
services.AddSignalR();
services.AddControllers();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
endpoints.MapHub<NotificationHub>("/Notifications");
});
}
I keep getting this error: System.IO.IOException: 'The server disconnected before the handshake could be started.' I must be missing something along the way here.
Update:
Turned on the logs and got this error:
dbug: Microsoft.AspNetCore.Http.Connections.Client.HttpConnection[8] Establishing connection with server at 'http://localhost:61514/notifications'. dbug: Microsoft.AspNetCore.Http.Connections.Client.HttpConnection[9] Established connection 'BdROAEEQnGUeDYAW5EspRA' with the server. dbug: Microsoft.AspNetCore.Http.Connections.Client.HttpConnection[7] Starting transport 'ServerSentEvents' with Url: http://localhost:61514/notifications. info: Microsoft.AspNetCore.Http.Connections.Client.Internal.ServerSentEventsTransport[1] Starting transport. Transfer mode: Text. dbug: Microsoft.AspNetCore.Http.Connections.Client.Internal.ServerSentEventsTransport[3] Starting receive loop. dbug: Microsoft.AspNetCore.Http.Connections.Client.Internal.ServerSentEventsTransport[9] Received 30 bytes. Parsing SSE frame. dbug: Microsoft.AspNetCore.Http.Connections.Client.Internal.ServerSentEventsTransport[4] Receive loop stopped. dbug: Microsoft.AspNetCore.Http.Connections.Client.Internal.ServerSentEventsTransport[100] Starting the send loop. dbug: Microsoft.AspNetCore.Http.Connections.Client.HttpConnection[18] Transport 'ServerSentEvents' started. dbug: Microsoft.AspNetCore.Http.Connections.Client.Internal.ServerSentEventsTransport[102] Send loop canceled. dbug: Microsoft.AspNetCore.Http.Connections.Client.Internal.ServerSentEventsTransport[101] Send loop stopped. Unhandled exception. info: Microsoft.AspNetCore.Http.Connections.Client.HttpConnection[3] HttpConnection Started. info: Microsoft.AspNetCore.SignalR.Client.HubConnection[24] Using HubProtocol 'json v1'. System.IO.IOException: The server disconnected before the handshake could be started. at Microsoft.AspNetCore.SignalR.Client.HubConnection.HandshakeAsync(ConnectionState startingConnectionState, CancellationToken cancellationToken) at Microsoft.AspNetCore.SignalR.Client.HubConnection.StartAsyncCore(CancellationToken cancellationToken) at Microsoft.AspNetCore.SignalR.Client.HubConnection.StartAsyncCore(CancellationToken cancellationToken) at Microsoft.AspNetCore.SignalR.Client.HubConnection.StartAsyncInner(CancellationToken cancellationToken) at System.Threading.Tasks.ForceAsyncAwaiter.GetResult() at Microsoft.AspNetCore.SignalR.Client.HubConnection.StartAsync(CancellationToken cancellationToken) at NotificationClient.Program.Main(String[] args)