如果经过身份验证的用户处于指定角色，为什么“授权角色”属性会拒绝访问？

Question

我将Asp.Net Core 2.1 Identity添加到了项目中。我能够成功注册用户并使用脚手架视图进行身份验证。

register.cs中有一些代码，可以自动将注册帐户分配给角色“ TestRole”，并在数据库中验证该角色已与测试帐户相关联。

userManager.AddToRoleAsync(user, "TestRole").Wait(); 当我添加[Authorize]属性route属性时，会得到预期的行为，或者如果用户未登录，则将其定向到登录屏幕。但是，当我使用[Authorize(Roles ="TestRole")]属性时，将被拒绝访问尽管已通过身份验证的帐户已与“ TestRole”相关联，但该页面仍显示在页面上

类似的SO QA（https://stackoverflow.com/a/46890346/1843966）在启动时验证了app.usemvc的顺序得到了一个流行的答案，但我已经确认自己做得很好。

当帐户与指定角色相关联时，什么会导致拒绝该请求？

StartUp.cs：

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

    public IConfiguration Configuration { get; }


    public void ConfigureServices(IServiceCollection services)
    {

        var context =  services.AddDbContextPool<myAppContext>( // replace "YourDbContext" with the class name of your DbContext
            options => options.UseMySQL("server=x.x.x.x;port=x;user=xyz;database=xyz;password=xyz")); 
            services.AddDefaultIdentity<myAppUser>()
                    .AddDefaultTokenProviders()
                    .AddRoles<IdentityRole>()
                    .AddEntityFrameworkStores<myAppContext>();
            services.AddAuthentication();
            services.AddMvc()
                    .AddJsonOptions(options => options.SerializerSettings.ContractResolver = new DefaultContractResolver());
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env, IServiceProvider service)
    {

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

dotnet控制台日志：

info: Microsoft.AspNetCore.Authorization.DefaultAuthorizationService[2]
  Authorization failed.
info: Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker[3]
  Authorization failed for the request at filter 
'Microsoft.AspNetCore.Mvc.Authorization.AuthorizeFilter'.
info: Microsoft.AspNetCore.Mvc.ForbidResult[1]
  Executing ForbidResult with authentication schemes ().
info: 
Microsoft.AspNetCore.Authentication.Cookies.CookieAuthenticationHandler[13]
  AuthenticationScheme: Identity.Application was forbidden.