Pros of Autofac

• More comprehensive IoC container with advanced features like modules and lifetime scoping
• Supports a wider range of registration and resolution scenarios
• Better performance for large-scale applications with many dependencies

Cons of Autofac

• Steeper learning curve due to its extensive feature set
• More complex setup and configuration compared to simpler DI solutions
• Potential for overengineering in smaller projects

Code Comparison

Scrutor (Assembly Scanning):

services.Scan(scan => scan
    .FromAssemblyOf<ITransientService>()
    .AddClasses(classes => classes.AssignableTo<ITransientService>())
    .AsImplementedInterfaces()
    .WithTransientLifetime());

Autofac (Assembly Scanning):

builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
    .Where(t => t.IsAssignableTo<ITransientService>())
    .AsImplementedInterfaces()
    .InstancePerDependency();

Both libraries offer assembly scanning capabilities, but Autofac provides more granular control over registration and lifetime management. Scrutor focuses on enhancing Microsoft.Extensions.DependencyInjection with scanning features, while Autofac is a full-fledged IoC container with broader functionality.

Pros of SimpleInjector

• More comprehensive dependency injection framework with advanced features
• Better performance in large-scale applications
• Supports automatic lifestyle management for registered components

Cons of SimpleInjector

• Steeper learning curve due to more complex API
• Requires more configuration and setup compared to Scrutor
• Less focused on assembly scanning and convention-based registration

Code Comparison

SimpleInjector:

var container = new Container();
container.Register<IUserRepository, SqlUserRepository>(Lifestyle.Singleton);
container.Register<IUserService, UserService>(Lifestyle.Transient);
container.Verify();

Scrutor:

services.Scan(scan => scan
    .FromAssemblyOf<IUserRepository>()
    .AddClasses(classes => classes.AssignableTo<IUserRepository>())
    .AsImplementedInterfaces()
    .WithSingletonLifetime());

SimpleInjector provides a more explicit registration approach, while Scrutor focuses on convention-based scanning and registration. SimpleInjector offers more control over component lifestyles, whereas Scrutor integrates seamlessly with Microsoft's dependency injection container.

Pros of Windsor

• Full-featured IoC container with advanced capabilities like interception, proxying, and lifecycle management
• Supports various component registration methods, including XML configuration and fluent API
• Mature project with extensive documentation and community support

Cons of Windsor

• Steeper learning curve due to its comprehensive feature set
• Can be overkill for simpler projects that only need basic dependency injection
• Slightly more complex setup and configuration compared to lightweight alternatives

Code Comparison

Windsor registration:

container.Register(Component.For<IService>().ImplementedBy<ServiceImpl>());

Scrutor registration:

services.Scan(scan => scan
    .FromAssemblyOf<IService>()
    .AddClasses(classes => classes.AssignableTo<IService>())
    .AsImplementedInterfaces());

Windsor focuses on explicit registration with a fluent API, while Scrutor emphasizes convention-based registration using assembly scanning. Windsor provides more control over component lifecycle and configuration, whereas Scrutor offers a simpler approach for common scenarios in ASP.NET Core applications.

Pros of Unity

• More comprehensive IoC container with advanced features like hierarchical containers and lifetime management
• Supports various injection methods (constructor, property, method)
• Extensive documentation and community support

Cons of Unity

• Heavier and more complex than Scrutor
• Steeper learning curve for beginners
• Less focused on assembly scanning and registration conventions

Code Comparison

Unity:

container.RegisterType<IService, ServiceImplementation>();
container.RegisterType<IRepository, Repository>(new ContainerControlledLifetimeManager());
var instance = container.Resolve<IService>();

Scrutor:

services.Scan(scan => scan
    .FromAssemblyOf<IService>()
    .AddClasses(classes => classes.AssignableTo<IService>())
    .AsImplementedInterfaces()
    .WithScopedLifetime());

Summary

Unity is a full-featured IoC container with more capabilities but higher complexity. Scrutor focuses on assembly scanning and registration conventions, offering a simpler approach for specific use cases. Unity is better suited for large, complex applications requiring advanced DI features, while Scrutor excels in scenarios where automatic registration and convention-based configuration are primary needs.

Pros of MediatR

• Implements the mediator pattern, promoting loose coupling and separation of concerns
• Supports both synchronous and asynchronous request/response handling
• Provides pipeline behaviors for cross-cutting concerns (e.g., logging, validation)

Cons of MediatR

• Requires more boilerplate code for defining request/handler classes
• Can lead to a proliferation of small classes in larger applications
• May introduce additional complexity for simpler scenarios

Code Comparison

MediatR:

public class GetUserQuery : IRequest<User> { }

public class GetUserHandler : IRequestHandler<GetUserQuery, User>
{
    public Task<User> Handle(GetUserQuery request, CancellationToken cancellationToken)
    {
        // Handler implementation
    }
}

Scrutor:

services.Scan(scan => scan
    .FromAssemblyOf<ITransientService>()
    .AddClasses(classes => classes.AssignableTo<ITransientService>())
    .AsImplementedInterfaces()
    .WithTransientLifetime());

While MediatR focuses on implementing the mediator pattern for decoupling request/response handling, Scrutor is primarily used for assembly scanning and automatic dependency registration. They serve different purposes in application architecture and can be used together in a project.