第一次调用 HTTPPOST 方法时 User.IsInRole 返回 false，但第二次调用它时返回 true

如何解决第一次调用 HTTPPOST 方法时 User.IsInRole 返回 false，但第二次调用它时返回 true

我正在从事授权/身份验证项目，目前正面临基于角色的身份验证问题。每当我尝试使用预先创建的用户帐户登录时，在实际登录之前，我都必须通过 HTTPPOST 两次。

用户已登录，但在通过 result.Succeeded 检查后，它无法识别登录的 User 是 Admin 角色。如果我再次单击登录按钮，它会像预期的那样通过 User.IsInRole("Admin") 检查。

HTTPPOST 方法：

    /// <summary>
    /// Logs a user in
    /// </summary>
    /// <param name="loginForm"></param>
    /// <returns></returns>
    [HttpPost]
    [AllowAnonymous]
    public async Task<IActionResult> Login(LoginForm loginForm)
    {
        // search for a user that matches the username and password from loginForm
        var result = await _signInManager.PasswordSignInAsync(loginForm.Username,loginForm.Password,true,false);

        // if a match is found,user is logged in
        if (result.Succeeded)
        {
            if (User.IsInRole("Admin"))
            {
                // create a viewbag of type List with all available licensetypes to later on show in a dropdown list
                ViewBag.LicenseTypes = Enum.GetValues(typeof(RegisterForm.Types))
                .Cast<RegisterForm.Types>()
                .Select(v => v.ToString())
                .ToList();

                return View("Register");
            }
            else if (User.IsInRole("Pirate"))
                return RedirectToAction(nameof(Index),"Ship");
        }
        return View();
    }

如果相关，种子数据：

        public static async Task SeedUsersAsync(UserManager<AppUser> userManager,RoleManager<IdentityRole> roleManager)
    {
        // create an admin role
        // check if an Admin user already exists
        if (userManager.FindByNameAsync("Admin").Result == null)
        {
            // create new identity user named Admin
            AppUser user = new AppUser
            {
                UserName = "Admin",LicensePlate = "Admin",LicenseType = "Z",SecretCode = "Admin123!"
            };
            
            IdentityResult result = userManager.CreateAsync(user,"Admin123!").Result;

            // check if user has been created succesfully
            if (result.Succeeded)
            {
                // check if an Admin role already exists
                if (!roleManager.RoleExistsAsync("Admin").Result)
                {
                    // create new identity admin role
                    IdentityRole role = new IdentityRole
                    {
                        Name = "Admin",NormalizedName = "ADMIN",ConcurrencyStamp = "Admin"
                    };

                    IdentityResult roleResult = roleManager.CreateAsync(role).Result;

                    // add claims to admin role
                    await roleManager.AddClaimAsync(role,new Claim("Username",user.UserName ?? ""));
                    await roleManager.AddClaimAsync(role,new Claim("Register Pirates","User can register temporary pirates"));

                    // check if user already has admin role
                    if (!await userManager.IsInRoleAsync(user,role.Name))
                    {
                        // add admin user to admin role
                        await userManager.AddToRoleAsync(user,role.Name);
                    }
                }
            }
        }

简而言之，为什么第一次不起作用？提前致谢。