Asp.net core 如何获取声明WSFederation cookie auth？

任何未经身份验证的web api用户都需要连接到ADFS。身份验证通过。现在我如何从cookie中获取userid声明

public IServiceProvider ConfigureServices(IServiceCollection services)
{
     services.AddMvc();

     services.AddAuthentication(o =>
     {
          o.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
          o.DefaultSignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
          o.DefaultChallengeScheme = WsFederationDefaults.AuthenticationScheme;
     }).AddWsFederation(o =>
     {
          o.Wtrealm = Configuration["Federation:Wtrealm"];
          o.MetadataAddress = Configuration["Federation:MetadataAddress"];
     }).AddCookie();
     return ContainerConfiguration.CreateAutofacServiceProvider(services);
}