Aspnet core signalr console app connection example

Question

User1448655074 posted

Hi

I have a server running .net 4.5.1 with SignalR (IIS)

I want to connect to the server using a console client app on .net core 2,2.  I have installed the below Nuget package on the client

Microsoft.AspNetCore.SignalR.Client;

and have followed https://docs.microsoft.com/en-us/aspnet/core/signalr/dotnet-client?view=aspnetcore-2.2

I keep getting the below error

"There was an error opening the connection:System.Net.Http.HttpRequestException: Response status code does not indicate success: 404 (Not Found)."

The name of my Hub on the server is correct so I'm not sure of the problem 

I have also tried

.WithUrl("http://172.10.0.20:81/client/?hub=myHub")

please help

connection = new HubConnectionBuilder()

//.WithUrl("http://172.10.0.20:81/client/?hub=myHub")

.WithUrl("http://172.10.0.20:81/myHub")

.Build();

connection.StartAsync().ContinueWith(task => {

if (task.IsFaulted)

{Console.WriteLine("There was an error opening the connection:{0}",

task.Exception.GetBaseException());}

else

{Console.WriteLine("Connected");}}).Wait();

connection.StartAsync();

Answer 1

User61956409 posted

Hi Poly,

Response status code does not indicate success: 404 (Not Found).

.WithUrl("http://172.10.0.20:81/myHub")

Please check whether you setup SignalR routes correctly, like below. And you can refer to [this article](https://docs.microsoft.com/en-us/aspnet/core/signalr/hubs?view=aspnetcore-2.2) to setup your SignalR hub.

app.UseSignalR(route =>
{
    route.MapHub<ChatHub>("/myHub");
});

Besides, I tried to host the SignalR Hub on my IIS server, and connect it from JavaScript Client and .NET Client (a console application), which work well on my side.

Setup SignalR routes

app.UseSignalR(routes =>
{
    routes.MapHub<ChatHub>("/chatHub");
});

Hub Class

public class ChatHub : Hub
{
    public async Task SendMessage(string user, string message)
    {       
        await Clients.All.SendAsync("ReceiveMessage", user, message);
    }
}

In Console App, connect to hub and call hub method

connection = new HubConnectionBuilder()
.WithUrl("http://xxx.xxx.xxx.xxx:9520/chatHub")
.Build();

await connection.StartAsync();

var mes = Console.ReadLine();

await connection.InvokeAsync("SendMessage", "Consloe Client", mes);

ReceiveMessage method definition

connection.On<string, string>("ReceiveMessage",
(string user, string message) =>
{
    Console.WriteLine($"Message from {user}: {message}");
});

Test Result:

With Regards,

Fei Han

Answer 2

User61956409 posted

Hi Poly

I have a server running .net 4.5.1 with SignalR (IIS)

In my previous reply, I am using AspNetCore SignalR build my hub.

If your hub server is built with ASP.NET SignalR, but the client application is built with ASP.NET Core SignalR, the client application would not able to connect to the server, because they are not compatible.

As I share in my previous reply, please refer to [this article](https://docs.microsoft.com/en-us/aspnet/core/signalr/hubs?view=aspnetcore-2.2) to build your SignalR hub.

With Regards,

Fei Han

Answer 3

User1448655074 posted

thanks that pushed me in the right direction.  

I'm using signalR with webforms so the hub is located at 

`http://172.10.0.20:82/signalr/myHub`

After changing path I got the below informative error

There was an error opening the connection:System.IO.InvalidDataException: Invalid negotiation response received. ---> System.InvalidOperationException: Detected a connection attempt to an ASP.NET SignalR Server. This client only supports connecting to an ASP.NET Core SignalR Server.

Answer 4

User61956409 posted

Hi Poly,

Detected a connection attempt to an ASP.NET SignalR Server. This client only supports connecting to an ASP.NET Core SignalR Server.

Your Hub server is built with AspNet.SignalR, if you'd like to build a console application to connect to your Hub, please refer to the following documentation to setup your client.

https://docs.microsoft.com/en-us/aspnet/signalr/overview/guide-to-the-api/hubs-api-guide-net-client#clientsetup

With Regards,

Fei Han