对cookie操作不太熟悉的可以参考一下。

 一般来说 cookie是个针对访问者电脑存储数据的东西，可以把一个cookie看作一个表，有表名，可以有很多行，每一行有两个字段，key和value，key唯一，可以通过key找到对应的值 value.

封装方法：

        #region 设置cookie
        /// <summary>
        /// 设置cookie
        /// </summary>
        /// <param name="key">键</param>
        /// <param name="value">值</param>
        /// <param name="cookiename">cookie名称</param>
        /// <param name="cookiedays">cookie保留多少天(默认3天)，可以用小数表示</param>
        public static void SetCookies(HttpResponseBase Response, HttpRequestBase Request, string key, string value, string cookiename,double cookiedays=3)
        {
            HttpCookie cookie = Request.Cookies[cookiename];
            //cookie.ExpirationSet = false;
            if (cookie == null)
            {
                cookie = new HttpCookie(cookiename);

                cookie.Values.Add(key, value);
            }
            else
            {
                if (cookie.Values[key] != null)
                {
                    cookie[key] = value;
                }
                else cookie.Values.Add(key, value);

            }
            if (HttpContext.Current != null)
            {
                if (HttpContext.Current.Request.Url.DnsSafeHost.Contains("kinpan.com"))
                {
                    cookie.Domain = "kinpan.com";
                }
            }
            //cookie.Domain = ConfigurationManager.AppSettings["kinpandomain"];
            cookie.Path = "/";
            cookie.Expires = DateTime.Now.AddDays(cookiedays);
            Response.Cookies.Remove(cookiename);
            Response.Cookies.Add(cookie);

        }
        #endregion

        #region 删除cookie
        /// <summary>
        /// 删除cookie，我们没有直接删除的权限，但是新建一个同名cookie,设置为过期，那么浏览器会去检测和删除同名的cookie。
        /// </summary>
        /// <param name="cookiename">cookie名称</param>
        public static void deleteCookie(HttpResponseBase Response,string cookiename)
        {
            if (cookiename.HasValue())
            {
                HttpCookie aCookie = new HttpCookie(cookiename);
                aCookie.Expires = DateTime.Now.AddDays(-1);
                Response.Cookies.Add(aCookie);
            }
        } 
        #endregion

        #region 获取整个cookie
        /// <summary>
        /// 获取整个cookie
        /// </summary>
        /// <param name="cookiename"></param>
        /// <returns></returns>
        public static HttpCookie GetCookie(HttpRequestBase Request, string cookiename)
        {
            return HttpContext.Current.Request.Cookies[cookiename];
        }
        #endregion

        #region 获取cookie里的键对应的值
        /// <summary>
        /// 获取cookie里的键对应的值
        /// </summary>
        /// <param name="name">名称</param>
        /// <param name="key">键</param>
        /// <returns>返回键对应的值</returns>
        public static string GetCookies(HttpRequestBase Request, string name, string key)
        {
            if (String.IsNullOrEmpty(name) || String.IsNullOrEmpty(key))
            {
                return String.Empty;
            }
            else
            {
                HttpCookie cookie = Request.Cookies[name];
                if (cookie != null && cookie[key] != null)
                {
                    string value = http://www.mamicode.com/cookie[key].ToString();>

.Net mvc cookie 操作封装方法