CSharp-Coder

Learn dependency injection in C# from scratch. Build loosely coupled, testable .NET code with runnable examples, service lifetimes and best practices. Start now! If you've opened an ASP.NET Core project, you've already used dependency injection in C# , even if you didn't know it. Controllers get services "for free," ILogger<T> just shows up, and Program.cs is full of AddScoped and AddSingleton calls. Many developers copy these lines without knowing why they work. In this tutorial we build dependency injection from scratch. We start with tightly coupled code, fix it by hand, write a small IoC container of our own, and then move to the built-in Microsoft.Extensions.DependencyInjection container. By the end you'll know how DI works, when to use each service lifetime, and how it makes your code much easier to unit test. What Is Dependency Injection in C#? Dependency injection (DI) is a design pattern. A class receives the objects it depends on...