无法从根提供程序解析作用域服务

当我尝试运行我的应用程序，我得到了错误

InvalidOperationException: Cannot resolve 'API.Domain.Data.Repositories.IEmailRepository' from root provider because it requires scoped service 'API.Domain.Data.EmailRouterContext'.

奇怪的是，这个 EmailRepository 和接口的设置与我所知道的所有其他存储库完全一样，但是没有为它们抛出错误。只有当我尝试使用该应用程序时才会出现错误。异常处理() ; 行。这是我的 Startup.cs 文件。

public class Startup
{
public IConfiguration Configuration { get; protected set; }
private APIEnvironment _environment { get; set; }


public Startup(IConfiguration configuration, IHostingEnvironment env)
{
Configuration = configuration;


_environment = APIEnvironment.Development;
if (env.IsProduction()) _environment = APIEnvironment.Production;
if (env.IsStaging()) _environment = APIEnvironment.Staging;
}


public void ConfigureServices(IServiceCollection services)
{
var dataConnect = new DataConnect(_environment);


services.AddDbContext<GeneralInfoContext>(opt => opt.UseSqlServer(dataConnect.GetConnectString(Database.GeneralInfo)));
services.AddDbContext<EmailRouterContext>(opt => opt.UseSqlServer(dataConnect.GetConnectString(Database.EmailRouter)));


services.AddWebEncoders();
services.AddMvc();


services.AddScoped<IGenInfoNoteRepository, GenInfoNoteRepository>();
services.AddScoped<IEventLogRepository, EventLogRepository>();
services.AddScoped<IStateRepository, StateRepository>();
services.AddScoped<IEmailRepository, EmailRepository>();
}


public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
loggerFactory.AddConsole();


app.UseAuthentication();


app.UseStatusCodePages();
app.UseEmailingExceptionHandling();


app.UseMvcWithDefaultRoute();
}
}

这里是 EmailRepository

public interface IEmailRepository
{
void SendEmail(Email email);
}


public class EmailRepository : IEmailRepository, IDisposable
{
private bool disposed;
private readonly EmailRouterContext edc;


public EmailRepository(EmailRouterContext emailRouterContext)
{
edc = emailRouterContext;
}


public void SendEmail(Email email)
{
edc.EmailMessages.Add(new EmailMessages
{
DateAdded = DateTime.Now,
FromAddress = email.FromAddress,
MailFormat = email.Format,
MessageBody = email.Body,
SubjectLine = email.Subject,
ToAddress = email.ToAddress
});
edc.SaveChanges();
}


public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}


private void Dispose(bool disposing)
{
if (!disposed)
{
if (disposing)
edc.Dispose();
disposed = true;
}
}
}

最后是异常处理中间件

public class ExceptionHandlingMiddleware
{
private const string ErrorEmailAddress = "errors@ourdomain.com";
private readonly IEmailRepository _emailRepository;


private readonly RequestDelegate _next;


public ExceptionHandlingMiddleware(RequestDelegate next, IEmailRepository emailRepository)
{
_next = next;
_emailRepository = emailRepository;
}


public async Task Invoke(HttpContext context)
{
try
{
await _next.Invoke(context);
}
catch (Exception ex)
{
await HandleExceptionAsync(context, ex, _emailRepository);
}
}


private static Task HandleExceptionAsync(HttpContext context, Exception exception,
IEmailRepository emailRepository)
{
var code = HttpStatusCode.InternalServerError; // 500 if unexpected


var email = new Email
{
Body = exception.Message,
FromAddress = ErrorEmailAddress,
Subject = "API Error",
ToAddress = ErrorEmailAddress
};


emailRepository.SendEmail(email);


context.Response.ContentType = "application/json";
context.Response.StatusCode = (int) code;
return context.Response.WriteAsync("An error occured.");
}
}


public static class AppErrorHandlingExtensions
{
public static IApplicationBuilder UseEmailingExceptionHandling(this IApplicationBuilder app)
{
if (app == null)
throw new ArgumentNullException(nameof(app));
return app.UseMiddleware<ExceptionHandlingMiddleware>();
}
}

更新: 我找到了这个链接 https://github.com/aspnet/DependencyInjection/issues/578，它让我改变了 Program.cs 文件的 BuildWebHost 方法

public static IWebHost BuildWebHost(string[] args)
{
return WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>()
.Build();
}

这个

public static IWebHost BuildWebHost(string[] args)
{
return WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>()
.UseDefaultServiceProvider(options =>
options.ValidateScopes = false)
.Build();
}

我不知道到底发生了什么，但现在看起来起作用了。