public static void SetObj(string strCookieName, int iExpires, string strValue)
        {
            HttpCookie objCookie = new HttpCookie(strCookieName.Trim());
            objCookie.Value = Utils.EncodeURIComponent(strValue.Trim());
            objCookie.Domain = N0.Config.CommonConfig.strDomain;
            if (iExpires > 0)
            {
                if (iExpires == 1)
                {
                    objCookie.Expires = DateTime.MaxValue;
                }
                else
                {
                    objCookie.Expires = DateTime.Now.AddSeconds(iExpires);
                }
            }
            HttpContext.Current.Response.Cookies.Add(objCookie);
        }

//构造cookie
            CookieContainer snCookie = new CookieContainer(50);
            snCookie .PerDomainCapacity = 50;

            CookieCollection sn132Collection3 = CookieArray.GetCookies(Datas.liveUri);
            for (int i = 0; i < sn132Collection3.Count; i++)
            {
                Cookie testC = new Cookie();
                testC = sn132Collection3[i];
                testC.Domain = "." + Datas.serverAddress;
                sn132Cookie.Add(new Uri(sendMailLink), testC);
            }

------解决方案--------------------
http://blog.csdn.net/porschev/archive/2011/05/10/6408543.aspx