ServiceResolver.GenericHost.SimpleInjector 3.8.0

ServiceResolver.GenericHost.SimpleInjector wires ServiceResolver.Ioc.SimpleInjector into Microsoft.Extensions.Hosting's IHostBuilder, replacing the default IServiceProvider with a SimpleInjector-backed one.

Getting started (console / worker apps)

var hostBuilder = Host.CreateDefaultBuilder(args)
    .UseServiceResolver(new SimpleInjectorOptions
    {
        OnRegistering = provider =>
        {
            provider.Register<StringBuilder>(() => new StringBuilder("hello world.."));
        },
        AfterBuildingProvider = provider =>
        {
            provider.Verify();
        }
    });

var host = hostBuilder.Build();

await host.RunAsync();

An overload taking Func<HostBuilderContext, SimpleInjectorOptions> is also available when you need access to configuration or environment during setup.

Getting started (ASP.NET Core, .NET 6+)

No extra package needed — UseServiceResolver replaces the app's IServiceProvider, and ASP.NET Core's own default IHttpContextFactory/IControllerActivator already give correct per-request scoping and controller activation against it.

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers();

builder.Host.UseServiceResolver(new SimpleInjectorOptions
{
    OnRegistering = serviceRegister =>
    {
        serviceRegister.Register<IMyScopedService, MyScopedService>(LifetimeScope.Scoped);
    },
    AfterBuildingProvider = provider =>
    {
        provider.Verify();
    }
});

var app = builder.Build();

app.UseAuthorization();
app.MapControllers();
await app.RunAsync();

Want controllers constructed (and disposed) by the native container instead of ASP.NET Core's own ActivatorUtilities-based activation — e.g. so Verify() above covers them too? Install ServiceResolver.GenericHost.AspNetCore and call serviceRegister.AddControllerActivation() from OnRegistering — its own readme covers this and the rest of that package's (optional) extension methods.

Constructor resolution: strict by default, relaxed where it has to be

By default (ConstructorResolutionType = ResolutionType.Hybrid), services registered through IServiceRegister keep SimpleInjector's strict rules (single public constructor, no optional-parameter fallback), while services coming from IServiceCollection (ASP.NET Core, third-party AddXxx() extensions) get a more permissive resolution — because those libraries routinely assume Microsoft's own, more lenient DI conventions. Set ConstructorResolutionType / SuppressDiagnosticType to ResolutionType.Standard (fully strict) or ResolutionType.LessRestrictive (relaxed everywhere) to change this globally.

Main types

• SimpleInjectorOptions — the configuration passed to UseServiceResolver.

Advanced scenarios that configure the underlying Container directly can use the public types under the ServiceResolver.Ioc.Advanced namespace, such as KeyedConstructorResolverBehavior and KeyedDependencyInjectionBehavior — see the documentation for details.

Related packages

• ServiceResolver.GenericHost
• ServiceResolver.Ioc.SimpleInjector
• ServiceResolver.GenericHost.AspNetCore (optional — native controller activation)