create an instance of Hub\signalR in AspNetCore

Question

in my case, messsage are come from internal events. no new request.

is there a way to create an Hub and send data to clients?

storing and resuse old Hub are crached with

'object is disposed..'

)

old frameworks has GlobalContext..

I have tried somthing like :

DataHub _hub =(DataHub) ServiceProvider.GetService(typeof(DataHub));
_hub.Clients.All.SendAsync("method");

but ServiceProvider also disposed.

Answer 1

based on https://www.c-sharpcorner.com/article/signal-r-with-asp-net-core-hosted-service-net-5/ the solution is using BackgroundService with Dependency Injection of IHubContext

this instance has long live (for my undestand ,while BackgroundService does not disposed).

public class HubMessageService : BackgroundService
    {
        IHubContext<DataHub> _hubContext;
        public HubMessageService(IHubContext<DataHub> hubContext)
        {
            _hubContext = hubContext ;
        }

in Startup.cs

public void ConfigureServices(IServiceCollection services)
        {
            services.AddHostedService<HubMessageService>();
            ...