/// <summary>
        /// 获得加密令牌
        /// </summary>
        /// <returns></returns>
        public static string EncryptToken<T>(T userData, int expireMinutes) where T : class
        {
            string strUserData = XmlUtil.ToXml(userData);

            FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(1, "HYFormsToken", DateTime.Now, DateTime.Now.AddMinutes(expireMinutes), true, strUserData);

            return FormsAuthentication.Encrypt(ticket);
        }

<system.web>
    <authentication mode="Forms" />
    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" maxRequestLength="40960" />
    <sessionState timeout="120"></sessionState>
    <globalization culture="zh-CN" fileEncoding="utf-8" responseHeaderEncoding="utf-8" requestEncoding="utf-8" responseEncoding="utf-8" uiCulture="zh-CN" />
  </system.web>

        /// <summary>
        /// 登录
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="userData"></param>
        /// <param name="expireMinutes"></param>
        /// <returns></returns>
        public static string DoLogin<T>(T userData, int expireMinutes) where T : class
        {
            string token = EncryptToken(userData, expireMinutes);

            HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName);

            cookie.Path = "/";
            cookie.Expires = DateTime.Now.AddMinutes(expireMinutes);
            cookie.Value = token;
            HttpContext.Current.Response.Cookies.Add(cookie);

            return token;
        }

        /// <summary>
        /// 将对象序列化为XML字符串
        /// </summary>
        /// <param name="obj">对象</param>
        /// <returns>对象的xml字符串</returns>
        public static string ToXml(object obj)
        {
            if (obj == null)
            {
                return null;
            }
            string xml;

            using (var stream = new MemoryStream())
            {
                var ser = new XmlSerializer(obj.GetType());

                ser.Serialize(stream, obj);

                var len = (int)stream.Position;

                var bufuer = stream.GetBuffer();

                xml = Encoding.UTF8.GetString(bufuer, 0, len);
            }

            return xml;
        }

        /// <summary>
        /// 从XML字符串反序列化类
        /// </summary>
        /// <typeparam name="T">目标类型</typeparam>
        /// <param name="xmlStr">对象的xml字符串</param>
        /// <returns>类型对象</returns>
        public static T FromXml<T>(string xmlStr)
        {
            Type type = typeof(T);
            return (T)new XmlSerializer(type).Deserialize(new StringReader(xmlStr));
        }

        /// <summary>
        /// 登出
        /// </summary>
        /// <returns></returns>
        public static bool Abandon()
        {
            FormsAuthentication.SignOut();
            HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName);
            cookie.Value = null;
            HttpContext.Current.Response.Cookies.Add(cookie);
            return true;
        }