WCF服务中操作FormsAuthentication的Cookie

 public interface IUserAuthenticate
    {
        [OperationContract]
 string VerifyUser(string username, string password,string appcode);
    }
   [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
 public class UserAuthenticate : IUserAuthenticate
   {
 public string VerifyUser(string username, string password, string appcode)
       {
           var appRep = new AppsRepository();
           AppInfo app = appRep.GetApp(appcode);
 if (app == null)
 return null;
           LoginUserStatus loginStatus = LoginUserStatus.Success;
 if (loginStatus == LoginUserStatus.Success)
           { 

               System.Web.Security.FormsAuthentication.SetAuthCookie(username, true);
 // 创建验证票
               System.Web.Configuration.FormsAuthenticationConfiguration formsConfig = new System.Web.Configuration.FormsAuthenticationConfiguration();
               FormsAuthenticationTicket formAuthTicket = new
                   FormsAuthenticationTicket(
 1,                              // 版本
                           username,                          // 用户名称
                           DateTime.Now,                   // 创建时间
                           DateTime.Now.AddMinutes(formsConfig.Timeout.TotalMinutes),    // 失效时间
 true,"");    // 用户数据 

 //加密票
 string encryptedTicket = FormsAuthentication.Encrypt(formAuthTicket);
 // 以加密票的密文存入Cookie
               HttpCookie authCookie = new HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket); 

               authCookie.HttpOnly = true;
               authCookie.Path = FormsAuthentication.FormsCookiePath;
               authCookie.Secure = FormsAuthentication.RequireSSL;
 if (FormsAuthentication.CookieDomain != null)
               {
                   authCookie.Domain = FormsAuthentication.CookieDomain;
               }
 if (formAuthTicket.IsPersistent)
               {
                   authCookie.Expires = formAuthTicket.Expiration;
               }
               HttpContext.Current.Response.Cookies.Add(authCookie);
               FormsIdentity identity = new FormsIdentity(formAuthTicket);
               GenericPrincipal principal = new GenericPrincipal(identity, null);
               HttpContext.Current.User = principal; 

               PassportTicket ticket = new PassportTicket(formAuthTicket, encryptedTicket, app);
 if (ticket.Save())
               {
 return ticket.Ticket.PublicTicket;
               }
 return null;
           }
 return null;
       }
   }