Register All Types (with Generic) in .NET Core DependencyInjection

ServiceCollectionExtentions.cs

using System;
using System.Linq;
using System.Reflection;
using Microsoft.Extensions.DependencyInjection;

public static class ServiceCollectionExtentions
{
    public static void AddAllTypes<T>(this IServiceCollection services
        , Assembly[] assemblies
        , bool additionalRegisterTypesByThemself = false
        , ServiceLifetime lifetime = ServiceLifetime.Transient
    )
    {
        var typesFromAssemblies = assemblies.SelectMany(a =>
            a.DefinedTypes.Where(x => x.GetInterfaces().Any(i => i == typeof(T))));
        foreach (var type in typesFromAssemblies)
        {
            services.Add(new ServiceDescriptor(typeof(T), type, lifetime));
            if (additionalRegisterTypesByThemself)
                services.Add(new ServiceDescriptor(type, type, lifetime));
        }
    }

    public static void AddAllGenericTypes(this IServiceCollection services
        , Type t
        , Assembly[] assemblies
        , bool additionalRegisterTypesByThemself = false
        , ServiceLifetime lifetime = ServiceLifetime.Transient
    )
    {
        var genericType = t;
        var typesFromAssemblies = assemblies.SelectMany(a => a.DefinedTypes.Where(x => x.GetInterfaces()
            .Any(i => i.IsGenericType && i.GetGenericTypeDefinition() == genericType)));

        foreach (var type in typesFromAssemblies)
        {
            services.Add(new ServiceDescriptor(t, type, lifetime));
            if (additionalRegisterTypesByThemself)
                services.Add(new ServiceDescriptor(type, type, lifetime));
        }
    }
}

Usage:

public void ConfigureServices(IServiceCollection services)
{
    services.AddAllTypes<IGenerator>(new[] { typeof(GenerateInvoiceHandler).GetTypeInfo().Assembly },

    //generic
    services.AddAllGenericTypes(typeof(IRequest<>), new[] {typeof(GenerateInvoiceHandler).GetTypeInfo().Assembly});
}

DodajPlikHandler what is this type

DodajPlikHandler is example file from project with you would like to search for types. It could be like: GenerateInvoiceCommand