c# - 无法解析非 ASP.NET Core 应用程序中类型 IOptions [DataAccessConfiguration] 的服务

Question

我们所有的业务服务之前都设置为使用带 IOptions 的依赖注入(inject)，因为它们被 ASP.NET Core 应用程序使用，如下所示:

NotificationDataAccess.cs:

public class NotificationDataAccess : BaseDataAccess, INotificationDac<Notification>
    {
        public NotificationDataAccess(IOptions<DataAccessConfiguration> options, IClaimsAccessor claimsAccessor) :
            base(options, claimsAccessor)
        {
        }
}

NotificationBusinessService.cs:

public class NotificationBusinessServices : INotificationServices<Notification>
    {
        private readonly INotificationDac<Notification> _notificationDataAccess;

        public NotificationBusinessServices(
            INotificationDac<Notification> notifcationDataAccess)
        {
            _notificationDataAccess = notifcationDataAccess;
        }
}

现在，我面临着一项艰巨的任务，即试图弄清楚如何从 Windows 服务中利用相同的模式，而这并没有从用于处理 DI 的内置 ASP.NET Core 功能中获益。当服务启动时，我执行以下代码:

// Set up configuration, services, and logging.
            IServiceCollection services = new ServiceCollection();
            var startup = new Startup();
            startup.ConfigureServices(services);
            IServiceProvider serviceProvider = services.BuildServiceProvider();

            var configuration = serviceProvider.GetService<IConfigurationRoot>();
            var notificationService = serviceProvider.GetService<INotificationServices<Notification>>();// TODO: This errors!
            processor = new Processor(configuration, notificationService);

这里是 Startup.cs 代码，应该配置服务:

public class Startup
    {
        IConfigurationRoot Configuration { get; }

        public Startup()
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(Path.Combine(AppContext.BaseDirectory))
                .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                .AddEnvironmentVariables();
            Configuration = builder.Build();
        }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddSingleton<IConfigurationRoot>(Configuration);
            //services.AddMvc();

            // Add application services.
            Listings.Business.Configuration.Instance = new BusinessLayerConfiguration();
            services.Configure<DataAccessConfiguration>(options => Configuration.GetSection("Data").Bind(options));
            services.AddScoped(typeof(INotificationDac<Notification>), typeof(NotificationDataAccess));
            services.AddScoped(typeof(INotificationServices<Notification>), typeof(NotificationBusinessServices));
        }
    }

不幸的是，当我运行 Windows 服务时，它在尝试获取通知服务时抛出异常:

var notificationService = serviceProvider.GetService<INotificationServices<Notification>>();

异常(exception)情况是:

System.InvalidOperationException: 'Unable to resolve service for type 'Microsoft.Extensions.Options.IOptions`1[Rpr.Listings.DataAccess.DataAccessConfiguration]' while attempting to activate 'Rpr.Listings.DataAccess.NotificationDataAccess'.'

我希望我的“services.Configure”代码能够解决这个问题，但遗憾的是没有。显然，我需要在我的 Startup.cs 中注册 IOptions，但我不知道该怎么做。这是 ASP.NET MVC 经常发生的事情吗？ “services.AddMvc();”通常正确注册此绑定(bind)？我可以调用它，但需要将大量 ASP.NET MVC 包导入到我的 Windows 服务中，我不愿意这样做。

请告诉我如何正确注册 IOptions 绑定(bind)，谢谢!

Answer 1

事实证明，我所缺少的只是:

services.AddOptions();

一旦我添加了它，IOptions 绑定(bind)就被正确注册了!