SignalR client service dependency injection

Question

I have implemented Microsoft.AspNetCore.SignalR.Client as a service. I can successfully inject it and send message to the hub. But I can't figure out how to listen to the hub (receive message) from that specific class.

I can receive message in HubClient with OnBroadcast action.

public class HubClient : IHub
{
    private HubConnection hubConnection;

    private async Task ConnectAsync()
    {
        // Connect

        hubConnection.On<string>("Broadcast", OnBroadcast); 
    }

    public async Task Send(string message)
    {
        await hubConnection.SendAsync("method", message);
    }

    private void OnBroadcast(string message)
    {
        // Received message
    }
}

How can I receive and process message from MyClass? How can I make OnBroadcast(string message) work in MyClass so that I can do something with message? I have multiple classes each of which has to process message from the hub.

public class MyClass
{
    private readonly IHub hub;

    public MyClass(IHub hub)
    {
        this.hub = hub;
    }

    public Task Send(string message)
    {
        // Sending message to the hub works
        await hub.Send(message);
    }

    // How can I process received messages here?
}

score 1 · Accepted Answer · answered Mar 20 '18 at 17:00

public interface IHub
{
    Task Send(string data);

    event Action<string> OnBroadcastAction;
}

public class HubClient : IHub
{
    private HubConnection hubConnection;

    public event Action<string> OnBroadcastAction;

    private async Task ConnectAsync()
    {
        // Connect

        hubConnection.On<string>("Broadcast", OnBroadcast);
    }

    public async Task Send(string message)
    {
        await hubConnection.SendAsync("method", message);
    }

    private void OnBroadcast(string message)
    {
        OnBroadcastAction?.Invoke(message);
    }
}

public class MyClass
{
    private readonly IHub hub;

    public MyClass(IHub hub)
    {
        this.hub = hub;
        hub.OnBroadcastAction += OnBroadcast;
    }

    public Task Send(string message)
    {
        await hub.Send(message);
    }

    private void OnBroadcast(string message)
    {
        Console.WriteLine(message);
    }
}

Where is the connection done in HubClient? and how can I use HubClient as a singleton in .net core? — RADU, Apr 25 '22 at 18:16

SignalR client service dependency injection

1 Answers1