MediatR instanciate command handler

Question

I don't know if anyone as ever had this problem. I'm trying to instance a class and get this error.

"Cannot resolve scoped service 'System.IServiceProvider' from root provider."

I even download the source code from MediatR to debug and try to understand the problem, but I didn't found any solution. Any help would be appreciated, because I'm stuck and can't find any solution on SO or Google This is the declaration of the class

public class UserAditionalDataHandler
    : BaseDbContextRequestHandler<UserAditionalDataCommand,
        UserAditionalDataAdded, SecuritySupportDbContext> 
{ 
    public UserAditionalDataHandler(
        IJsonStringLocalizer stringLocalizer, 
        ILogger logger,
        IMapper mapper,
        IMediator mediator, 
        IDatabaseContextProviderFactory databaseFactory)
    : base(
        stringLocalizer,
        logger,
        mapper,
        mediator,
        databaseFactory) { } 
}

The base class inherits from IRequestHandler<TReq, TRes>

This is the registration:

public static IServiceCollection AddServiceMediatR(
    this IServiceCollection services,
    Func<IEnumerable<Assembly>> InjectAssemblies,
    Func<IServiceCollection, IServiceCollection>
        InjectMediatRDecorators)
{
    var assemblies = InjectAssemblies()
        .Where(x => x.FullName.Contains(
            "CommandsHandlers",
            StringComparison.OrdinalIgnoreCase))
        .ToArray();

    if (assemblies.Length > 0)
    {
        services.AddMediatR(
            options => options.AsScoped(), assemblies);
        InjectMediatRDecorators(services);
    }

    return services;
}

This is the full stack trace of the exception.

at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution(Type serviceType, IServiceScope scope, IServiceScope rootScope)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.Microsoft.Extensions.DependencyInjection.ServiceLookup.IServiceProviderEngineCallback.OnResolve(Type serviceType, IServiceScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
at Microsoft.Extensions.Options.OptionsBuilder1.<>c__DisplayClass9_01.<Configure>b__0(IServiceProvider sp)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitDisposeCache(ServiceCallSite transientCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitIEnumerable(IEnumerableCallSite enumerableCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitNoCache(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitDisposeCache(ServiceCallSite transientCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.ResolveService(ServiceCallSite callSite, RuntimeResolverContext context, RuntimeResolverLock lockType, ServiceProviderEngineScope serviceProviderEngine)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitRootCache(ServiceCallSite callSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.b__0(ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceCollectionExtensions.<>c.b__12_2(IServiceProvider sp)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.ResolveService(ServiceCallSite callSite, RuntimeResolverContext context, RuntimeResolverLock lockType, ServiceProviderEngineScope serviceProviderEngine)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitRootCache(ServiceCallSite callSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceCollectionExtensions.<>c.<AddAutoMapperClasses>b__12_3(IServiceProvider sp)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitDisposeCache(ServiceCallSite transientCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitDisposeCache(ServiceCallSite transientCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
at MediatR.ServiceFactoryExtensions.GetInstance[T](ServiceFactory factory) in C:\Repos\W\src\MediatR\ServiceFactory.cs:line 16
at MediatR.Wrappers.RequestHandlerBase.GetHandler[THandler](ServiceFactory factory) in C:\Repos\W\src\MediatR\Wrappers\RequestHandlerWrapper.cs:line 20

public static IServiceCollection AddServiceMediatR(this IServiceCollection services, Func> InjectAssemblies, Func InjectMediatRDecorators) { var assemblies = InjectAssemblies().Where(x => x.FullName.Contains("CommandsHandlers", StringComparison.OrdinalIgnoreCase)).ToArray(); if (assemblies.Length > 0) { services.AddMediatR(options => options.AsScoped(), assemblies); InjectMediatRDecorators(services); } return services; } — Ruben Monteiro, Jun 08 '21 at 10:51

score 0 · Answer 1 · answered Jun 09 '21 at 11:56

I don't why but it's working. I rebuild the solution several times but always got the same error, yesterday I started to change the code of a class in the same dll of this one and today I tried once more, it started to work, I don't know how, but I can only say that it could be cache issues in visual studio.

MediatR instanciate command handler

1 Answers1