c# - 未配置身份验证处理程序来处理方案：Microsoft.AspNet.Identity.Application when using ASP.NET Core Identity

Question

当我尝试登录用户时出现错误：

public async Task<bool> SignIn(string email, string password)
{
    var user = await this._userManager.FindByEmailAsync(email);
    if (user == null)
        return false;

    if (await this._userManager.CheckPasswordAsync(user, password))
    {
        await this._signInManager.SignInAsync(user, false); //error
        return true;
    }
    return false;
}

我的 Startup.cs 如下所示：

    public Startup(IHostingEnvironment env)
    {
        var builder = new ConfigurationBuilder()
            .AddJsonFile("appsettings.json")
            .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true);

        if (env.IsDevelopment())
        {
            builder.AddUserSecrets();
        }

        builder.AddEnvironmentVariables();
        Configuration = builder.Build();
    }

    public IConfigurationRoot Configuration { get; set; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddTransient<RoleManager<IdentityRole>>();
        services.AddTransient<UserManager<ApplicationUser>>();
        services.AddTransient<SignInManager<ApplicationUser>>();

        // Add framework services.
        services.AddEntityFramework()
            .AddSqlServer()
            .AddDbContext<DbContext>(options =>
                options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));

        services.AddIdentity<ApplicationUser, IdentityRole>()
            .AddEntityFrameworkStores<DbContext>()
            .AddDefaultTokenProviders();

        services.AddMvc(config =>
        {
        #if !DEBUG
            config.Filters.Add(new RequireHttpsAttribute());
        #endif
        }).AddJsonOptions(opts =>
        {
            opts.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
        }); ;

        services.AddSingleton<IAccountService, AccountService>();
        services.AddSingleton<IAgencyService, AgencyService>();
        services.AddSingleton<IFeatureService, FeatureService>();
        ....
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
    {
        loggerFactory.AddConsole(Configuration.GetSection("Logging"));
        loggerFactory.AddDebug();

        if (env.IsDevelopment())
        {
            app.UseBrowserLink();
            app.UseDeveloperExceptionPage();
            app.UseDatabaseErrorPage();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");

            try
            {
                using (var serviceScope = app.ApplicationServices.GetRequiredService<IServiceScopeFactory>()
                    .CreateScope())
                {
                    serviceScope.ServiceProvider.GetService<DbContext>()
                         .Database.Migrate();
                }
            }
            catch { }
        }

        app.UseIISPlatformHandler(options => options.AuthenticationDescriptions.Clear());

        app.UseStaticFiles();

        app.UseIdentity();

        app.UseMvc(routes =>
        {
            ... routes

        });

        SeedGenerator.Initialize(app.ApplicationServices);
    }

    public static void Main(string[] args) => WebApplication.Run<Startup>(args);