无法使用表单身份验证注销

Question

我们在项目中使用了子域，而Form身份验证则用于登录和注销，无法从其他域注销。

仅FormsAuthentication.SignOut（）;代码无法退出。所以我用下面的代码：

FormsAuthentication.SignOut();
Session.Abandon();

HttpCookie cookie1 = new HttpCookie(FormsAuthentication.FormsCookieName, "");
cookie1.Expires = DateTime.Now.AddYears(-1);
Response.Cookies.Add(cookie1);

SessionStateSection sessionStateSection = (SessionStateSection)WebConfigurationManager.GetSection("system.web/sessionState");
HttpCookie cookie2 = new HttpCookie(sessionStateSection.CookieName, "");
cookie2.Expires = DateTime.Now.AddYears(-1);
Response.Cookies.Add(cookie2);

还是不行..！