基本类-CookieStorage

简单建立Cookie：

public enum CookieKey
    {
        UserLogin
    }

    public class CookieStorage
    {
        private const int LOGINEXPIRESTIME = 24 * 60;
        public static object SetCookie(CookieKey key, string value)
        {
            HttpCookie cookie = HttpContext.Current.Request.Cookies[key.ToString()];
            if (cookie == null)
            {
                cookie = new HttpCookie(key.ToString());
                string result = HttpUtility.UrlEncode(value);
                cookie.Value = result;
                cookie.Expires = System.DateTime.Now.AddMinutes(LOGINEXPIRESTIME);
                HttpContext.Current.Response.Cookies.Add(cookie);
            }

            return value;
        }

        public static string GetCookie(CookieKey key)
        {
            HttpCookie cookie = HttpContext.Current.Request.Cookies[key.ToString()];
            if (cookie != null)
            {
                string result = HttpUtility.UrlDecode(cookie.Value);
                return result;
            }

            return string.Empty;
        }

        public static void ClearCookie(CookieKey key) {
             HttpCookie cookie = HttpContext.Current.Request.Cookies[key.ToString()];
             if (cookie != null)
             {
                 cookie.Expires = DateTime.Now.AddDays(-1);
                 HttpContext.Current.Response.Cookies.Add(cookie);
             }
        }
    }