I would like to create a SignalR Self hosting Server within a console app using .NetCore.
I am completely new to web development and .Net Core but would like to use SignalR as a real-time web based protocol. No web page is required, and so I would like to have a console app.
I have successfully tested the .Net Framework example below and would like to replicate this using .Net Core 3.1, so that it can run on Linux. However I cannot find any suitable examples.
using System;
using Microsoft.AspNet.SignalR;
using Microsoft.Owin.Hosting;
using Owin;
using Microsoft.Owin.Cors;
namespace SignalRSelfHost
{
class Program
{
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/library/system.net.httplistener.aspx
// for more information.
string url = "http://localhost:8088";
using (WebApp.Start<Startup>(url))
{
Console.WriteLine("Server running on {0}", url);
Console.ReadLine();
}
}
}
class Startup
{
public void Configuration(IAppBuilder app)
{
app.UseCors(CorsOptions.AllowAll);
app.MapSignalR();
}
}
public class MyHub : Hub
{
public void Send(string name, string message)
{
Clients.All.addMessage(name, message);
Clients.All.addMessage(name, "World");
}
}
}
In an attempt to use Owin to create a server console app I have the following code and this compiles, however complains about no server service being registered when I run the program. Could someone please advise what to add to have a web server without web page? The example I copied specified UseKestrel() but I think this is for a web page, so I think I need something else.
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
namespace OwinConsole
{
public class Startup
{
// For more information on how to configure your application, visit http://go.microsoft.com/fwlink/?LinkID=398940
public void ConfigureServices(IServiceCollection services)
{
}
public void Configure(IApplicationBuilder app)
{
app.UseOwin(pipeline =>
{
pipeline(next => OwinHello);
});
}
public Task OwinHello(IDictionary<string, object> environment)
{
string responseText = "Hello World via OWIN";
byte[] responseBytes = Encoding.UTF8.GetBytes(responseText);
// OWIN Environment Keys: http://owin.org/spec/spec/owin-1.0.0.html
var responseStream = (Stream)environment["owin.ResponseBody"];
var responseHeaders = (IDictionary<string, string[]>)environment["owin.ResponseHeaders"];
responseHeaders["Content-Length"] = new string[] { responseBytes.Length.ToString(CultureInfo.InvariantCulture) };
responseHeaders["Content-Type"] = new string[] { "text/plain" };
return responseStream.WriteAsync(responseBytes, 0, responseBytes.Length);
}
}
}
using System.IO;
using Microsoft.AspNetCore.Hosting;
namespace OwinConsole
{
public class Program
{
public static void Main(string[] args)
{
var host = new WebHostBuilder()
.UseContentRoot(Directory.GetCurrentDirectory())
.UseStartup<Startup>()
.Build();
host.Run();
}
}
}
Thanks.
As mentioned by Noah, my solution was based on
But instead was built as a console app referencing Microsoft.AspNetCore.App (2.2.8).
ChatHub
using Microsoft.AspNetCore.SignalR;
using System.Threading.Tasks;
namespace SignalRServer
{
public class ChatHub : Hub
{
public async Task SendMessage(string user, string message)
{
await Clients.All.SendAsync("ReceiveMessage", user, message);
}
}
}
Startup
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
namespace SignalRServer
{
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
//services.AddRazorPages();
services.AddSignalR();
}
// 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();
}
else
{
app.UseExceptionHandler("/Error");
// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
//endpoints.MapRazorPages();
endpoints.MapHub<ChatHub>("/chatHub");
});
}
}
}
Program
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Hosting;
namespace SignalRServer
{
public class Program
{
public static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
webBuilder.UseUrls("http://localhost:2803");
});
}
}