How to get SignalR Hub Context in a ASP.NET Core?
IConnectionManager does not exist any more in SignalR for ASP.Net Core.
I've been using HubContext
for getting access to a hub.
public class HomeController : Controller
{
private readonly IHubContext<LiveHub> _hubContext;
public HomeController(IHubContext<LiveHub> hubContext)
{
_hubContext = hubContext;
}
public void SendToAll(string message)
{
_hubContext.Clients.All.InvokeAsync("Send", message);
}
}
I'm using .net core 2.0.0 and SignalR 1.0.0-alpha1-final
I added some code to my Startup.cs to grab reference to the ConnectionManager which you can then use to do a GetHubContext at anytime from anywhere in your code. Similar to Nimo's answer but a little different, maybe simpler.
services.AddSignalR(options =>
{
options.Hubs.EnableDetailedErrors = true;
});
var provider = services.BuildServiceProvider();
//Hold on to the reference to the connectionManager
var connManager = provider.GetService(typeof(IConnectionManager)) as IConnectionManager;
//Use it somewhere else
var hub = connManager.GetHubContext<SignalHub>();
Microsoft.AspNet.SignalR.Infrastructure.IConnectionManager
is a DI injected service through which you can get the hub context...For example:
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Infrastructure;
using Microsoft.AspNet.Mvc;
public class TestController : Controller
{
private IHubContext testHub;
public TestController(IConnectionManager connectionManager)
{
testHub = connectionManager.GetHubContext<TestHub>();
}
.....
To use the hub in a backgroud service, in addition to controllers, you must use the IHostedService interface and get the hub by DI.
public class MyBackgroundService : IHostedService, IDisposable
{
public static IHubContext<NotifierHub> HubContext;
public MyBackgroundService(IHubContext<NotifierHub> hubContext)
{
HubContext = hubContext;
}
public Task StartAsync(CancellationToken cancellationToken)
{
//TODO: your start logic, some timers, singletons, etc
return Task.CompletedTask;
}
public Task StopAsync(CancellationToken cancellationToken)
{
//TODO: your stop logic
return Task.CompletedTask;
}
public void Dispose()
{
}
}
Then you can call your hub from anywhere in your code from HubContext static field:
MyBackgroundService.HubContext.Clients.All.SendAsync("UpdateData", myData).Wait();
Learn more about IHostedService: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/host/hosted-services?view=aspnetcore-2.1
You can create and start a timer in MyBackgroundService and call the hub in ElapsedEvent.