‫روشی برای محاسبه‌ی تعداد کاربران آنلاین در ASP.NET Core

public class OnlineUserMiddleWare
    {
        private readonly RequestDelegate _next;
        private readonly IMemoryCache _memoryCache;

        public OnlineUserMiddleWare(RequestDelegate next, IMemoryCache memoryCache)
        {
            _next = next;
            _memoryCache = memoryCache;
        }

        public async Task Invoke(HttpContext context)
        {
            if (!_memoryCache.TryGetValue("OnlineUsers", out Dictionary<string,DateTime> onlineUsers))
            {
                onlineUsers = new Dictionary<string, DateTime>();
                _memoryCache.Set("OnlineUsers", onlineUsers);
            }
            if (context.User.Identity.IsAuthenticated)
            {
                var name = context.User.Identity.Name;
                if (name != null)
                {
                    if (onlineUsers.ContainsKey(name))
                        onlineUsers[name] = DateTime.Now;
                    else
                        onlineUsers.Add(name, DateTime.Now);
                }

            }

           
                foreach (var online in onlineUsers)
                {
                    if (online.Value < DateTime.Now.AddMinutes(-10))
                        onlineUsers.Remove(online.Key);
                }
           
            await _next(context);
        }

        
    }

 public void Configure(IApplicationBuilder app, IWebHostEnvironment env, IServiceProvider serviceProvider)
        {
         ...
            app.UseMiddleware<OnlineUserMiddleWare>();
         ...
        }

public class DashboardController 
    {
        private readonly IMemoryCache _memoryCache;
        public DashboardController(memoryCache)
        {
            _memoryCache = memoryCache;
        }
        public IActionResult Index()
        {
         
            _memoryCache.TryGetValue("OnlineUsers", out Dictionary<string, DateTime> onlineUsers);
            ViewBag.OnlineUsers = onlineUsers.Count;
            return View();
        }       
    }

           if(context.Request.Path.StartsWithSegments("/Identity/Account/Login"))
            {
                foreach (var online in onlineUsers)
                {
                    if (online.Value < DateTime.Now.AddMinutes(-10))
                        onlineUsers.Remove(online.Key);
                }
            }