MTWorkHR/MTWorkHR.API/Chat/ChatHub.cs

using Microsoft.AspNetCore.SignalR;

namespace MTWorkHR.API.Chat
{
    public sealed class ChatHub : Hub<IChatClient>
    {

        public override async Task OnConnectedAsync()
        {
            await Clients.All.ReceiveMessage($"{Context.ConnectionId} has joined");
        }
        public async Task SendMessage(string message)
        {
            await Clients.All.ReceiveMessage($"{Context.ConnectionId} :{message}");
        }


        public async Task askServer(string someTextFromClient)
        {
            string tempString;

            if (someTextFromClient == "hey")
            {
                tempString = "message was 'hey'";
            }
            else
            {
                tempString = "message was something else";
            }

            await Clients.Client(this.Context.ConnectionId).ReceiveMessage(tempString);
        }
    }
}