remember me(isPersistent) dont work on Forms authentication - asp.net

Question

Here my cookie create code:
This is controller (model.RememberMe is a checkbox value)
int timeout = (model.RememberMe) ? (int) FormsAuthentication.Timeout.TotalMinutes : Session.Timeout;//4h
HttpCookie cookie = accountService.GetCookie(userId, model.RememberMe, timeout);
Response.Cookies.Add(cookie);
Logger.Debug("POST: AccountController LogOn end.");
result = returnUrl != null
? RedirectToLocal(returnUrl)
: RedirectToAction("Index", "Profile", new {id = userId});
Service method that's create cookie
public HttpCookie GetCookie(int userId, bool rememberMe, int timeout)
{
Logger.Trace("AccountService GetCookie start with arguments:" +
" userId = {0}, rememberMe = {1}.", userId, rememberMe);
var authTicket = new FormsAuthenticationTicket(
1,
Convert.ToString(userId),
DateTime.Now,
DateTime.Now.AddMinutes(timeout),
rememberMe,
string.Empty,
"/"
);
HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName,
FormsAuthentication.Encrypt(authTicket));
Logger.Debug("Cookie for user with userId = {0} has created", userId);
Logger.Trace("AccountService GetCookie end.");
return cookie;
}
But unfortunately RememberMe dont work and cookies expires at the end of the browser session.Why?
What is the purpose of FormsAuthenticationTicket isPersistent property? Here some kind of answer but i dont understand why it doesnt work?

Answer 1

The difference between your code and the SO answer that you linked is that they use:
FormsAuthentication.SetAuthCookie(model.UserName, true);
Which makes the cookie with proper expiration time based on the IsPersistent property. However, if you return the cookie with the constructor like in your code:
HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName,
FormsAuthentication.Encrypt(authTicket));
Then the expiration time will be set to browser-session because that is the default behavior of the HttpCookie class: what is the default expiration time of a cookie
So you probably have two options. Use the FormsAuthentication.SetAuthCookie method outlined in the answer you linked to, or add:
cookie.Expires = DateTime.Now.AddMinutes(10); // or whatever you want