c# – appSettings.json中的自定义键在ASP.NET Core 2.0中不起作

{
  "ConnectionStrings": {
    "DefaultConnectionString": "Data Source=..."
  },"Logging": {
    "IncludeScopes": false,"LogLevel": {
      "Default": "Warning"
    }
  },"CustomSettings": {
    "Culture": "es-CO"
  }
}

我无法在以下控制器中加载Culture键：

public AccountController(
            UserManager<ApplicationUser> userManager,SignInManager<ApplicationUser> signInManager,IEmailSender emailSender,ILogger<AccountController> logger,IConfiguration configuration)
{
   Response.Cookies.Append(
                    CookieRequestCultureProvider.DefaultCookieName,CookieRequestCultureProvider.MakeCookieValue(new RequestCulture(configuration.GetSection("CustomSettings")["Culture"])),new CookieOptions { Expires = DateTimeOffset.UtcNow.AddYears(1) }
            );
}

无论我是否遵循,总是返回NULL：
configuration.GetSection( “CustomSettings”)[ “文化”];
configuration.GetSection( “CustomSettings”)的GetValue( “文化”).

我尝试了基于ASP.NET Core: Step by Step Guide to Access appsettings.json in web project and class library的帮助,并且我创建了具有字符串Culture属性的CustomSettings类,并在Startup中注入如下：

// Load Custom Configuration from AppSettings.json
        services.Configure<Models.CustomSettings>(Configuration.GetSection("CustomSettings"));

通过注入IOptions来访问customSettings,其值为
customSettings.Value.Culture返回NULL.

第一个问题：?我做错了什么或缺少什么？

第二个问题：?为什么在HomeController的索引中执行以下操作会引发异常？

public class HomeController : Controller
{
   public IActionResult Index(IConfiguration configuration)
   {
   }
}

例外：

处理请求时发生未处理的异常.
InvalidOperationException：无法创建类型为’Microsoft.Extensions.Options.IOptions`1 [[OmniMerchant.Models.CustomSettings,OmniMerchant,Version = 1.0.0.0,Culture = neutral,PublicKeyToken = null]]’的实例.模型绑定的复杂类型不能是抽象或值类型,并且必须具有无参数构造函数.

Microsoft.AspNetCore.Mvc.ModelBinding.Binders.ComplexTypeModelBinder.CreateModel(ModelBindingContext bindingContext)

第三个问题：我需要根据appSettings.json上的Culture属性为后台的所有应用程序设置Culture,我读了MSDN documentation,但是我无法实现这一点,?我怎样才能实现这个目标？

谢谢