Question

I created a server hub in an asp.net application like below

public class Calc : Hub
{
    public void CalculateSomething(int a, int b)
    {
        // start working in a new thread
        var task = Task.Factory.StartNew(() => DoCalculate(a, b));

        // attach a continuation task to notify
        // the client when the work is done
        task.ContinueWith(t =>
        {
            System.Threading.Thread.Sleep(2000);
            Clients.addMessage(t.Result);
            Caller.notifyCalculateResult(t.Result);
            System.Threading.Thread.Sleep(2000);
            Caller.notifyCalculateResult("Completed");
            Clients.addMessage("Completed");
        });
    }

    private int DoCalculate(int p1, int p2)
    {
        // do some slow work on the input,
        // e.g. call webservice or I/O.
        int result = p1 + p2;
        //int result = DoSlowWork(p1, p2);
        return result;
    }
}

Now in another asp.net application I created a client using SiganlR client. But it’s not working correctly. I am looking to get data from server as it pushes to client

using System.Threading.Tasks;
using SignalR;
using SignalR.Client;
using SignalR.Client.Hubs;
namespace WebApplication2
{
    public partial class _Default : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            // Connect to the service
            var hubConnection = new HubConnection("http://localhost:3119/");

            // Create a proxy to the chat service
            var chat = hubConnection.CreateProxy("Calc");

            // Print the message when it comes in
            chat.On("addMessage", message =>Print(message));

            // Start the connection
            hubConnection.Start().Wait();

            // Send a message to the server
            chat.Invoke("CalculateSomething", 1, 2).Wait();
        }

        private async void Print(object message)
        {
            Response.Write(message);
        }
    }
}

The console client application works fine. The main problem is with asp.net beacause it fails to the handle call back from server.

Answer 1

Looks like you calling the server side method wrongly, try this

chat.Invoke("CalculateSomething", 1, 2).ContinueWith(task =>
{ 
  Console.WriteLine("Value from server {0}", task.Result);
});