在票证超时之前会话数据丢失

Question

我尝试通过在web.config中设置authentication / forms / timeout值，并在登录页面FormsAuthenticationTicket.expiration中设置代码，在我的网站上设置相当长的60分钟会话时间。但是，已经在20分钟内，太早了，我的Session变量中的数据丢失了。这是如何工作的，我该如何解决？

的Web.config：

<authentication mode="Forms">
  <forms name="MYWEBAPP.ASPXAUTH" 
    loginUrl="~/Login.aspx" 
    protection="All" 
    timeout="60"                   /* <<------ */         
    slidingExpiration="true" 
    path="/"/>
</authentication>

login.aspx.cs：

            // Create a new ticket used for authentication
            FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(
                1,                                      // Ticket version
                LoggedInUser.LoginNm.ToString(),        // Username associated with ticket
                DateTime.Now,                           // Date/time issued
                DateTime.Now.AddMinutes(60), // <<---   // Date/time to expire, minutes, use same value as in web.config or result is unclear
                false,                                  // "true" for a persistent user cookie
                LoggedInUser.UserID.ToString(),         // User-data, in this case user object
                FormsAuthentication.FormsCookiePath);   // Path cookie valid for

            // Encrypt the ticket and store in a cookie
            string CookieName = FormsAuthentication.FormsCookieName;
            string CookieValue = FormsAuthentication.Encrypt(ticket);
            cookie = new HttpCookie(CookieName, CookieValue);

            // Set the cookie's expiration time to the tickets expiration time, plus a little to be sure.
            // NB: the cookie is created and updated with "sliding" reset automatically
            //  if the SetAuth...()  coockie call was used
            // NB: Persistent is false, so this is a Session cookie without expiration 
            //     that is deleted when the browser closes.
            //if (ticket.IsPersistent)
            {
                cookie.Expires = ticket.Expiration.AddMinutes(5);
            }

在form.aspx.cs中检查会话是否仍然存在：

protected void Page_PreInit(object sender, EventArgs e)
{
    // Load settings from session variabele
    MySession = Session["MySession"] as ClSession;
    // return to loginpage indien sessionvar = null
    if (MySession == null)
        Response.Redirect("~/SessionExpired.html"); // <<---after only 20 minutes!!??
    return;
}