问会话是否可用

EN

protected void Save(Query query, string queryTitle)
{
    // would probably be better to refactor this bit out into its own method
    string sCookieHeader = Request.Headers["Cookie"];
    if (Context.Session != null 
        && Context.Session.IsNewSession
        && sCookieHeader != null
        && sCookieHeader.IndexOf("ASP.NET_SessionId") >= 0)
    {
        // session has expired
        if (Request.IsAuthenticated)
        {
            FormsAuthentication.SignOut();
        }
        Response.StatusCode = 401
    }
    else
    {
        // we're authenticated, so do the save
    }
}

$.ajax(serverUrl, {
   data: dataToSave,
   statusCode: {
      200: function(response) {
        // all good, continue
      401: function (response) {
         // session expired!
         // show login box
         // make ajax call to reauthenticate
         // call save method again
      },
});

public ActionResult Reauthenticate(username, password) 
{
    if (IsValidUser(username, password))
    {  
      // sometimes used to persist user roles
      string userData = string.Join("|",GetCustomUserRoles());

      FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(
        1,                                     // ticket version
        username,                              // authenticated username
        DateTime.Now,                          // issueDate
        DateTime.Now.AddMinutes(30),           // expiryDate
        isPersistent,                          // true to persist across browser sessions
        userData,                              // can be used to store additional user data
        FormsAuthentication.FormsCookiePath);  // the path for the cookie

      // Encrypt the ticket using the machine key
      string encryptedTicket = FormsAuthentication.Encrypt(ticket);

      // Add the cookie to the request to save it
      HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket);
      cookie.HttpOnly = true; 
      Response.Cookies.Add(cookie);
    }
}

public void Save()
{
    if (Session.IsNewSession)
    {
        throw new Exception("This session was just created.");
    }

    //Go on with save matter...
}