NET 6 - Dependency Injection
Last modified: March 25, 2022ASP.NET 6 has a built-in dependency injection (DI) software design pattern, that is to achieve Inversion of Control (IOC) between classes and their dependencies. In a traditional ASP.NET without DI, do we as below
public class AnimalService
{
private readonly MyDependency _dependency = new MyDependency();
public void OnGet()
{
_dependency.walk();
}
}
The AnimalService class fully depends on MyDependency and should be avoided for the following reasons
- If we want to replace MyDependency, then AnimalService must be modified
- if MyDependency depends on something else, then it must be configured in AnimalService
- Unit test is difficult to conduct.
Dependency injection solves these problems by following
- By use of an interface to abstract the implementation
- DI register in a service container and ASP.NET 6 has a built-in service container in Startup.ConfigureServices method.
- Injection of service in the constructor when it is used and framework disposes of it when it is no longer needed.
Program.cs
- In .NET 5 or before, we used to register a DI in Startup.cs file
- However in .NET 6, we register a DI in Program.cs
In all free UI projects; MVC, Razor Pages, and Web API. Register the following Repositories
- You need to add Core and Infrastructure projects to this.
builder.Services.AddScoped<IEventRepository, EventRepository>();
builder.Services.AddScoped<IEventBookingRepository, EventBookingRepository>();
