Dependency Injection in .NET and ASP.NET Core

Explore the dependency injection design pattern and the open-closed principle, showing how low coupling across presentation, business, and data access layers avoids changes when swapping databases in dotnet.

Use interfaces to reduce coupling among the user interface, business, and data access, and rely on dependency injection to instantiate and call methods through those interfaces.

Show how to reduce UI coupling by using interfaces like IBusiness and IDataAccess and implement concrete data access classes, with constructor-based dependency injection.

Apply constructor injection to decouple the UI and business layers by passing I data access and I business from the main program, avoiding new statements inside concrete classes.

Examine .NET dependency injection lifetimes: singleton, scoped, and transient, detailing one app-wide instance, per-request instances across threads, and new-injection instances, illustrated with a simple sequence diagram.

Explore AddScoped and AddTransient in Microsoft Extensions Dependency Injection with a service collection and provider, showing that scoped instances stay the same per scope while transient ones change.

Create a small ASP.NET Core MVC blog app to study dependency injection with add scope and add singleton. Explore DynamoDB v2 integration and auto-injected interfaces, attributes, and filters.

Learn to secure post methods by creating a protector attribute as an action filter, inject an authorizer via dependency injection, and apply it with service filter for per-request authorization.

Configure logging in ASP.NET Core via dependency injection, inject an ILogger<T>, and log errors, information, or exceptions; switch to serilog or NLog for advanced targets like Elasticsearch.

Use the dotnet core dependency injection framework in WPF core applications by registering the main window and a test class, building a service provider, and injecting into the main window.

Plug a third-party IoC container like Autofac into the .NET dependency injection framework in ASP.NET Core, migrate registrations, and leverage module-based configuration for cleaner service setup.

Engage with interview questions and answers on dependency injection, pausing between prompts to reflect on why each answer is best, and deepen your understanding for interviews and work.

Registering this class with dependency injection is unsafe for both transient and scoped lifetimes. The static primary keys list is shared app-wide, causing race conditions because lists are not thread-safe.

Learn how service collection stores metadata and mappings while the service provider creates instances and manages lifetimes, explaining why build service provider is needed for dependency resolution.

Register I certificate to birth certificate in startup class with scoped lifetime, and inject employee via constructor for per-request creation.