asp.net 二级域名表单认证情况下共享Cookie

二级域名之间共享Cookie，很重要的一点就是配置,如下：

domain设置为.ahdqxx.com，如果你的域名是www.ahdqxx.com,mall.ahdqxx.com,那么请设置你的domain为.ahdqxx.com

path设置为/

<authentication mode="Forms">
      <forms name="DQ.AUTH" loginUrl="http://www.ahdqxx.com/Login/Index" protection="All" domain=".ahdqxx.com" timeout="43200" path="/" requireSSL="false" slidingExpiration="true" />
    </authentication>

第二重点的就是登陆时候Cookie设置，

不要忘记使用之前配置的东西来设置 Cookie（FormsAuthentication.FormsCookiePath，FormsAuthentication.CookieDomain）

      public virtual void SignIn(Customer customer, bool createPersistentCookie)

        {

            var now = DateTime.UtcNow.ToLocalTime();
var userdata = JsonConvert.SerializeObject(new SimpleUser { Name = _customerSettings.UsernamesEnabled ? customer.Username : customer.Email, ID = customer.CustomerGuid });
var ticket = new FormsAuthenticationTicket(

                1 /*version*/,

                _customerSettings.UsernamesEnabled ? customer.Username : customer.Email,

                now,

                now.Add(_expirationTimeSpan),

                createPersistentCookie,

                userdata,

                FormsAuthentication.FormsCookiePath);
var encryptedTicket = FormsAuthentication.Encrypt(ticket);
var cookie = new HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket);

            cookie.HttpOnly = true;

            if (ticket.IsPersistent)

            {

                cookie.Expires = ticket.Expiration;

            }

            cookie.Secure = FormsAuthentication.RequireSSL;

            cookie.Path = FormsAuthentication.FormsCookiePath;

            if (FormsAuthentication.CookieDomain != null)

            {

                cookie.Domain = FormsAuthentication.CookieDomain;

            }
_httpContext.Response.Cookies.Add(cookie);

            _cachedCustomer = customer;

        }

容易犯得的错误，如果你在配置中使用了machineKey节点，请保证相关站点使用相同的machineKey