设置共享Cookie:
二级域名要想共享一级域名的cookie,只需要设置cookie.Domain = ".一级域名.com";
删除共享Cookie:
HttpCookie cookie = HttpContext.Current.Request.Cookies["A"]; if (cookie != null) { cookie.Expires = DateTime.Now.AddDays(-1); cookie.Domain = "一级域名.com";(注:不要www) cookie.Path = "/"; cookie.Values.Clear(); context.Response.Cookies.Add(cookie); }