Get list of online users in asp.net mvc

Question

I have a page in my application that always shows an updated list of online users. Now, to save the list that is stored in the updated object, I follow these steps

• add user to the list at login

• delete user at logout

• Then, to handle browser close / navigation operations, I have a timestamp along with the username in the collection. An Ajax call updates the timestamp every 90 seconds.

Problem: I need to clear this list every 120 seconds to remove entries with old timestamps.

How to do this in my web application? those. call a function every 2 minutes.

PS: I thought about calling webservice every 2 minutes using the scheduler, but the hosting environment does not allow scheduling.

Answer 1

Do the following inside the global filter.

public class TrackLoginsFilter : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        Dictionary<string, DateTime> loggedInUsers = SecurityHelper.GetLoggedInUsers();

        if (HttpContext.Current.User.Identity.IsAuthenticated )
        {
            if (loggedInUsers.ContainsKey(HttpContext.Current.User.Identity.Name))
            {
                loggedInUsers[HttpContext.Current.User.Identity.Name] = System.DateTime.Now;
            }
            else
            {
                loggedInUsers.Add(HttpContext.Current.User.Identity.Name, System.DateTime.Now);
            }

        }

        // remove users where time exceeds session timeout
        var keys = loggedInUsers.Where(u => DateTime.Now.Subtract(u.Value).Minutes >
                   HttpContext.Current.Session.Timeout).Select(u => u.Key);
        foreach (var key in keys)
        {
            loggedInUsers.Remove(key);
        }

    }
}

To get a list of users

public static class SecurityHelper
{
    public static Dictionary<string, DateTime> GetLoggedInUsers()
    {
        Dictionary<string, DateTime> loggedInUsers = new Dictionary<string, DateTime>();

        if (HttpContext.Current != null)
        {
            loggedInUsers = (Dictionary<string, DateTime>)HttpContext.Current.Application["loggedinusers"];
            if (loggedInUsers == null)
            {
                loggedInUsers = new Dictionary<string, DateTime>();
                HttpContext.Current.Application["loggedinusers"] = loggedInUsers;
            }
        }
        return loggedInUsers;

    }
}

Remember to register the filter in global.asax. It would probably be nice to set up the application to disable it.

GlobalFilters.Filters.Add(new TrackLoginsFilter());

Also remove users when logging out to be more accurate.

SecurityHelper.GetLoggedInUsers().Remove(WebSecurity.CurrentUserName);

Answer 2

In account controller

   public ActionResult Login(LoginModel model, string returnUrl)
    {
        if (ModelState.IsValid)
        {
            if (Membership.ValidateUser(model.UserName, model.Password))
            {
                FormsAuthentication.SetAuthCookie(model.UserName, model.RememberMe);
                if (HttpRuntime.Cache["LoggedInUsers"] != null) //if the list exists, add this user to it
                {
                    //get the list of logged in users from the cache
                    List<string> loggedInUsers = (List<string>)HttpRuntime.Cache["LoggedInUsers"];
                    //add this user to the list
                    loggedInUsers.Add(model.UserName);
                    //add the list back into the cache
                    HttpRuntime.Cache["LoggedInUsers"] = loggedInUsers;
                }
                else //the list does not exist so create it
                {
                    //create a new list
                    List<string> loggedInUsers = new List<string>();
                    //add this user to the list
                    loggedInUsers.Add(model.UserName);
                    //add the list into the cache
                    HttpRuntime.Cache["LoggedInUsers"] = loggedInUsers;
                }
                if (!String.IsNullOrEmpty(returnUrl))
                {
                    return Redirect(returnUrl);
                }
                else
                {

                    return RedirectToAction("Index", "Home");
                }
            }
            else
            {
                ModelState.AddModelError("", "The user name or password provided is incorrect.");
            }
        }

        // If we got this far, something failed, redisplay form
        return View(model);
    }


    public ActionResult LogOff()
    {
        string username = User.Identity.Name; //get the users username who is logged in
        if (HttpRuntime.Cache["LoggedInUsers"] != null)//check if the list has been created
        {
            //the list is not null so we retrieve it from the cache
            List<string> loggedInUsers = (List<string>)HttpRuntime.Cache["LoggedInUsers"];
            if (loggedInUsers.Contains(username))//if the user is in the list
            {
                //then remove them
                loggedInUsers.Remove(username);
            }
            // else do nothing
        }
        //else do nothing
        FormsAuthentication.SignOut();
        return RedirectToAction("Index", "Home");
    }

in partial representation.

@if (HttpRuntime.Cache["LoggedInUsers"] != null)
{
    List<string> LoggedOnUsers = (List<string>)HttpRuntime.Cache["LoggedInUsers"];
    if (LoggedOnUsers.Count > 0)
    {
    <div class="ChatBox">
        <ul>
            @foreach (string user in LoggedOnUsers)
            {
                <li>
                    <div class="r_row">
                       <div class="r_name">@Html.Encode(user)</div>
                    </div>
                </li>
            }
        </ul>
    </div>
    }
}

display this partial view when the user logs in.

use this script call in 90 seconds

<script type="text/javascript">
    $(function () {
        setInterval(loginDisplay, 90000);
    });

    function loginDisplay() {
        $.post("/Account/getLoginUser", null, function (data) {

        });
    }
</script>

Answer 3

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Answer 4

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http://www.codeproject.com/KB/aspnet/ASPNETService.aspx

Answer 5

Ajax " " 30 . , .