Every serious .NET codebase you will ever work on uses dependency injection.It is built into ASP.NET Core. It is in the project template you get from dotnet new. It is in the constructor of nearly every controller, service, and repository written in the last decade. And it is one of the most common topics in .NET technical interviews.
Yet most developers learn it backwards. They copy a line like builder.Services.AddScoped from a tutorial, it works, and they move on — without ever understanding what the container is doing, why the interface is there, or what would break if they used AddSingleton instead.
The course Dependency Injection in C# and .NET: The Complete Guide!
fixes that. It teaches dependency injection from first principles: what problem it actually solves, the design principle it comes from, the patterns used to apply it, and only then, how the built-in .NET container implements it.
Who is this for?
Ideal for C# developers with a working knowledge of OOP — classes, interfaces, inheritance, polymorphism. And anyone preparing for a C# or .NET interview, where DI, IoC and service lifetimes are near-guaranteed questions, can benefit from this course.
Software Required
Demonstrations use Visual Studio 2022 and the .NET SDK. The dependency injection concepts, the design patterns, and the Microsoft.Extensions.DependencyInjection container API taught here are stable across modern .NET — everything in this course applies equally whether you're on .NET 8, .NET 9, or .NET 10, and works the same in Visual Studio 2022, Visual Studio 2026, VS Code, or Rider. You are welcome to follow along on whatever setup you already have.
What You Will Learn
- Define what dependency injection (DI) really is
- Lean the Dependency Inversion Principle
- See exactly what tight coupling costs you
- Apply the Dependency Inversion Principle
- The various Dependency injection Design Patterns
- Understand lifetime management
- Learn what interception is and what it enables
- Get comfortable with the built-in .NET DI container