asp.net mvc3，cookie

Question

我有一个网站，用户可以通过他们的Facebook帐户或Twitter进行身份验证： 要知道我使用cookie的用户：

的Global.asax：

protected void Application_AuthenticateRequest(Object sender, EventArgs e)
    {
        HttpCookie authCookie = Request.Cookies[FormsAuthentication.FormsCookieName];
        if (authCookie != null)
        {
            var authTicket = FormsAuthentication.Decrypt(authCookie.Value);
            var id = new MyIdentity(authTicket);
            var userData = authTicket.UserData.Split(',');

            id.SocialProviderName = userData[0].Replace("providerslist=", "").Split('|')[0];
            var newUser = new MyPrincipal(id);
            Context.User = newUser;
        }

    }

用户可以链接两个帐户（Facebook和Twitter）。与连接 twitter然后点击“帐户关联”，将重定向到她的Facebook帐户进行身份验证

问题是当重定向到第二个帐户时，cookie变为空并且

if（this.HttpContext.Request.IsAuthenticated）             {...}

返回false

（如果我使用单个帐户连接，则cookie无效）

我的控制器：

...

FormsAuthentication.SetAuthCookie（socialProfile.UserId，true）;

ResetFormsCookie（providerName，socialProfile.UserId）;

...

UserID由GUID生成

  public void ResetFormsCookie(string providerName, string userId)
    {
        var authCookie = HttpContext.Current.ApplicationInstance.Request.Cookies[FormsAuthentication.FormsCookieName];
        if (authCookie == null)
        {
            authCookie = FormsAuthentication.GetAuthCookie(userId, true);
        }
        var authTicket = FormsAuthentication.Decrypt(authCookie.Value);
        var userData = authTicket.UserData;
        var providerslist = (from c in userData.Split(',') where c.Contains("providerslist=") select c).FirstOrDefault();
        if (string.IsNullOrEmpty(providerslist))
        {
            userData += string.IsNullOrEmpty(userData) ? "providerslist=" + providerName : ",providerslist=" + providerName;
        }
        else
        {
            if (!providerslist.Contains(providerName))
            {
                userData = userData.Replace(providerslist, providerslist + "|" + providerName);
            }
        }
        var newTicket = new FormsAuthenticationTicket(authTicket.Version, authTicket.Name, authTicket.IssueDate
            , DateTime.Now.AddDays(90) // authTicket.Expiration ToDo: This need to set in the config
        , authTicket.IsPersistent, userData);
        authCookie.Value = FormsAuthentication.Encrypt(newTicket);
        HttpContext.Current.Response.Cookies.Add(authCookie);
    }

我为我的英语道歉

谢谢，