Is there a small example of a console or winform app using signalR to send a message to a .net hub?. I have tried the .net examples and have looked at the wiki but it is not making sense to me the relationship between the hub(.net) and client(console app) (could not find an example of this). Does the app just need the address and name of hub to connect?.
If someone could provide a small tidbit of code showing the app connecting to a hub and sending "Hello World" or something that the .net hub receives?.
PS. I have a standard hub chat example which works well , if I try to assign a hub name in Cs to it , it stops working i.e [HubName("test")] , do you know the reason for this?.
Thanks.
Current Console app Code.
static void Main(string[] args)
{
//Set connection
var connection = new HubConnection("http://localhost:41627/");
//Make proxy to hub based on hub name on server
var myHub = connection.CreateProxy("chat");
//Start connection
connection.Start().ContinueWith(task =>
{
if (task.IsFaulted)
{
Console.WriteLine("There was an error opening the connection:{0}", task.Exception.GetBaseException());
}
else
{
Console.WriteLine("Connected");
}
}).Wait();
//connection.StateChanged += connection_StateChanged;
myHub.Invoke("Send", "HELLO World ").ContinueWith(task => {
if(task.IsFaulted)
{
Console.WriteLine("There was an error calling send: {0}",task.Exception.GetBaseException());
}
else
{
Console.WriteLine("Send Complete.");
}
});
}
Hub Server. (different project workspace)
public class Chat : Hub
{
public void Send(string message)
{
// Call the addMessage method on all clients
Clients.addMessage(message);
}
}
Info Wiki for this is http://www.asp.net/signalr/overview/signalr-20/hubs-api/hubs-api-guide-net-client
Example for SignalR 2.2.1 (May 2017)
Server
Install-Package Microsoft.AspNet.SignalR.SelfHost -Version 2.2.1
[assembly: OwinStartup(typeof(Program.Startup))]
namespace ConsoleApplication116_SignalRServer
{
class Program
{
static IDisposable SignalR;
static void Main(string[] args)
{
string url = "http://127.0.0.1:8088";
SignalR = WebApp.Start(url);
Console.ReadKey();
}
public class Startup
{
public void Configuration(IAppBuilder app)
{
app.UseCors(CorsOptions.AllowAll);
/* CAMEL CASE & JSON DATE FORMATTING
use SignalRContractResolver from
https://stackoverflow.com/questions/30005575/signalr-use-camel-case
var settings = new JsonSerializerSettings()
{
DateFormatHandling = DateFormatHandling.IsoDateFormat,
DateTimeZoneHandling = DateTimeZoneHandling.Utc
};
settings.ContractResolver = new SignalRContractResolver();
var serializer = JsonSerializer.Create(settings);
GlobalHost.DependencyResolver.Register(typeof(JsonSerializer), () => serializer);
*/
app.MapSignalR();
}
}
[HubName("MyHub")]
public class MyHub : Hub
{
public void Send(string name, string message)
{
Clients.All.addMessage(name, message);
}
}
}
}
Client
(almost the same as Mehrdad Bahrainy reply)
Install-Package Microsoft.AspNet.SignalR.Client -Version 2.2.1
namespace ConsoleApplication116_SignalRClient
{
class Program
{
private static void Main(string[] args)
{
var connection = new HubConnection("http://127.0.0.1:8088/");
var myHub = connection.CreateHubProxy("MyHub");
Console.WriteLine("Enter your name");
string name = Console.ReadLine();
connection.Start().ContinueWith(task => {
if (task.IsFaulted)
{
Console.WriteLine("There was an error opening the connection:{0}", task.Exception.GetBaseException());
}
else
{
Console.WriteLine("Connected");
myHub.On<string, string>("addMessage", (s1, s2) => {
Console.WriteLine(s1 + ": " + s2);
});
while (true)
{
Console.WriteLine("Please Enter Message");
string message = Console.ReadLine();
if (string.IsNullOrEmpty(message))
{
break;
}
myHub.Invoke<string>("Send", name, message).ContinueWith(task1 => {
if (task1.IsFaulted)
{
Console.WriteLine("There was an error calling send: {0}", task1.Exception.GetBaseException());
}
else
{
Console.WriteLine(task1.Result);
}
});
}
}
}).Wait();
Console.Read();
connection.Stop();
}
}
}
To build on @dyslexicanaboko's answer for dotnet core, here is a client console application:
Create a helper class:
using System;
using Microsoft.AspNetCore.SignalR.Client;
namespace com.stackoverflow.SignalRClientConsoleApp
{
public class SignalRConnection
{
public async void Start()
{
var url = "http://signalr-server-url/hubname";
var connection = new HubConnectionBuilder()
.WithUrl(url)
.WithAutomaticReconnect()
.Build();
// receive a message from the hub
connection.On<string, string>("ReceiveMessage", (user, message) => OnReceiveMessage(user, message));
var t = connection.StartAsync();
t.Wait();
// send a message to the hub
await connection.InvokeAsync("SendMessage", "ConsoleApp", "Message from the console app");
}
private void OnReceiveMessage(string user, string message)
{
Console.WriteLine($"{user}: {message}");
}
}
}
Then implement in your console app's entry point:
using System;
namespace com.stackoverflow.SignalRClientConsoleApp
{
class Program
{
static void Main(string[] args)
{
var signalRConnection = new SignalRConnection();
signalRConnection.Start();
Console.Read();
}
}
}
The Self-Host now uses Owin. Checkout http://www.asp.net/signalr/overview/signalr-20/getting-started-with-signalr-20/tutorial-signalr-20-self-host to setup the server. It's compatible with the client code above.
This is for dot net core 2.1 - after a lot of trial and error I finally got this to work flawlessly:
var url = "Hub URL goes here";
var connection = new HubConnectionBuilder()
.WithUrl($"{url}")
.WithAutomaticReconnect() //I don't think this is totally required, but can't hurt either
.Build();
//Start the connection
var t = connection.StartAsync();
//Wait for the connection to complete
t.Wait();
//Make your call - but in this case don't wait for a response
//if your goal is to set it and forget it
await connection.InvokeAsync("SendMessage", "User-Server", "Message from the server");
This code is from your typical SignalR poor man's chat client. The problem that I and what seems like a lot of other people have run into is establishing a connection before attempting to send a message to the hub. This is critical, so it is important to wait for the asynchronous task to complete - which means we are making it synchronous by waiting for the task to complete.
Source: Stackoverflow.com