为什么 LinkGenerator 总是返回 null？

Question

我编写了一个类来为其他类（Aspnet 核心 3.1）生成链接，这些类发送带有链接的电子邮件，这些链接通过 DI 获取 LinkGenerator 的实例。

每当我在 LinkGenerator 的实例上调用任何方法时，它都会返回 null。我做错了吗？

 public interface IPageLinkGenerator
    {
        string LinkFor(string page, object values);
    }

    public class PageLinkGenerator : IPageLinkGenerator
    {
        private readonly IHttpContextAccessor _accessor;
        private readonly LinkGenerator _generator;

        public PageLinkGenerator(IHttpContextAccessor accessor, LinkGenerator generator)
        {
            _accessor = accessor;
            _generator = generator;
        }

        public string LinkFor(string page, object values)
        {
            var context = _accessor.HttpContext;

            var callBackLink = _generator.GetUriByPage(
                context,
                page: page,
                handler: null,
                values: values,
                scheme: context.Request.Scheme,
                host: context.Request.Host
                );

            return callBackLink;
        }
    }

这是我在 Startup.cs 中的 ConfigureServices 方法

public void ConfigureContainer(ServiceRegistry services)
        {
            services.Scan(_ =>
            {
                _.AssemblyContainingType<IDbConnectionFactory>();
                _.WithDefaultConventions();
                _.ConnectImplementationsToTypesClosing(typeof(IHandle<>));
            });

            services.For<IConfiguration>().Use(Configuration);
            services.For<IStorageClient>().Use<AzureBlobClient>();
            services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
            services.AddSingleton<IDomainEventDispatcher, DomainEventDispatcher>();
            services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
            services.AddScoped(typeof(IAsyncRepository<>), typeof(EfRepository<>));
            services.AddScoped(typeof(IValidationRepository<>), typeof(ValidationRepository<>));
            
            services.AddCustomisedDbContext(Configuration);
            services.AddHtmlTags(new TagConventions());
            services.AddMediatR(typeof(Startup));

            services.For<IRazorLightEngine>()
                .Use(RazorLightEngineFactory.Get())
                .Singleton();

            services.AddTestConfigurationInstance(_environment, Configuration);
            services.AddEmailSender(_environment);

            services.AddProxyHttpClient();

            services.AddCustomisedIdentity(_environment, Configuration);

            services.AddAuthorizationPolicies(Configuration);

            services.AddCustomisedRazorPages();

            services.AddWkhtmltopdf();

            services.AddLocalization();
            
            services.AddRouting();
        }

这是调用类的方法：

public async Task Handle(BookingAdminMessageCreated @event, CancellationToken cancellationToken)
    {
        var url = _linkGenerator.LinkFor("/Customers/Bookings/Messages", new { Id = @event.BookingId.ToString() });
        
        foreach (var (fullName, emailAddress) in @event.EmailDetails)
        {
            await _emailSender.SendAsync(emailAddress, MailType.MessageAdded, new Dictionary<string, dynamic>
            {
                {"FullName", fullName},
                {"ReferenceNumber", @event.Reference},
                {"BookingUrl", HtmlEncoder.Default.Encode(url)},
            });
        }
    }

Answer 1

问题是我错过了页面中的页面名称。我没有指定索引页面。

_linkGenerator.LinkFor("/Customers/Bookings/Messages/Index" ...