如何在ASP.NET Core 2.0中设置多个身份验证方案？

var authenticationBuilder = services.AddAuthentication(options =>
{
    options.AddScheme("myauth",builder =>
    {
        builder.HandlerType = typeof(CookieAuthenticationHandler);
    });
})
    .AddCookie();

我在控制器中的登录代码如下所示：

var claims = new List<Claim>
{
    new Claim(ClaimTypes.Name,user.Name)
};

var props = new AuthenticationProperties
{
    IsPersistent = persistCookie,ExpiresUtc = DateTime.UtcNow.AddYears(1)
};

var id = new ClaimsIdentity(claims);
await HttpContext.SignInAsync("myauth",new ClaimsPrincipal(id),props);

但是当我在控制器或动作过滤器中时,我只有一个身份,并且它不是经过身份验证的身份：

var identity = context.HttpContext.User.Identities.SingleOrDefault(x => x.AuthenticationType == "myauth");

导航这些变化一直很困难,但我猜我正在做.AddScheme错了.有什么建议？

编辑：这里(基本上)是一个干净的应用程序,不会在User.Identies上产生两组身份：

namespace WebApplication1.Controllers
{
    public class Testy : Controller
    {
        public IActionResult Index()
        {
            var i = HttpContext.User.Identities;
            return Content("index");
        }

        public async Task<IActionResult> In1()
        {
            var claims = new List<Claim> { new Claim(ClaimTypes.Name,"In1 name") };
            var props = new AuthenticationProperties  { IsPersistent = true,ExpiresUtc = DateTime.UtcNow.AddYears(1) };
            var id = new ClaimsIdentity(claims);
            await HttpContext.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme,props);
            return Content("In1");
        }

        public async Task<IActionResult> In2()
        {
            var claims = new List<Claim> { new Claim(ClaimTypes.Name,"a2 name") };
            var props = new AuthenticationProperties { IsPersistent = true,ExpiresUtc = DateTime.UtcNow.AddYears(1) };
            var id = new ClaimsIdentity(claims);
            await HttpContext.SignInAsync("a2",props);
            return Content("In2");
        }

        public async Task<IActionResult> Out1()
        {
            await HttpContext.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);
            return Content("Out1");
        }

        public async Task<IActionResult> Out2()
        {
            await HttpContext.SignOutAsync("a2");
            return Content("Out2");
        }
    }
}

和初创公司：

namespace WebApplication1
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddAuthentication(options =>
            {
                options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
                })
                .AddCookie(CookieAuthenticationDefaults.AuthenticationScheme)
                .AddCookie("a2");

            services.AddMvc();
        }

        public void Configure(IApplicationBuilder app,IHostingEnvironment env)
        {
            app.UseAuthentication();

            app.UseMvc(routes =>
            {
                routes.MapRoute(name: "default",template: "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}