LinkedIn
GitHub profile
Проекты
Advertisement
RSS
.NET Framework .NET C# VB.NET LINQ ASP.NET Web API REST SignalR Windows Forms WPF WCF RabbitMQ PHP SQL Server MySQL PostgreSQL MariaDB SQLite MongoDB ADO.NET ORM Entity Framework Dapper XML JSON HTML5 CSS3 Bootstrap JavaScript jQuery Angular React TypeScript NPM Blazor UI/UX Responsive Web Design Redis Elasticsearch GraphQL Grafana Agile Scrum Kanban Windows Server IIS PowerShell Active Directory TFS Azure Automation Software Reverse Engineering Performance Optimization Git Jira/Confluence CI/CD TeamCity SOLID KISS DRY YAGNI
Always will be ready notify the world about expectations as easy as possible: job change page

Simple Dependency Injection in .Net 6.0 Web API

Created: Jan 18, 2023
Author: Jay
Source: https://medium.com/projectwt/simple-dependency-injection-in-net-6-0-web-api-24164e56f8f8
Views: 48

Aha! There is always something intimidating about Dependency Injection. I distinctly remember a couple of years ago, telling a .Net recruiter for a contract project, that,

“I had no idea what DI is”

He immediately stopped talking to me. It’s just one of those moments.

It was true, to an extent. It’s one of those things that you have been doing for years, but, you never knew you were doing it.

Like how you unconsciously woo women in college and accidentally end up with a girlfriend.

Or, when you watch so many English movies since childhood, you are accidentally making yourself an excellent speaker of English, without being aware of it.

Anyway, that’s neither here nor there. Let’s get back to, DI.

As always, the code is available here.

Core Idea

DI gets its name from the final, 5th, enter in SOLID principles. The 5th entry of SOLID says the following.

  1. High-level modules should not import anything from low-level modules. Both should depend on abstractions (e.g., interfaces).
  2. Abstractions should not depend on details. Details (concrete implementations) should depend on abstractions.

Step One — Interface and Implementations

Right then. First up, you want to create an interface and and it’s implementation.

public interface ISayMyName
{
    public string IAmName();
}

public class SayMyNameOne : ISayMyName
{
    public string IAmName()
    {
        var name = "I am Batman!";

        return name;
    }
}

public class SayMyNameTwo : ISayMyName
{
    public string IAmName()
    {
        var name = "I am Vengence!";

        return name;
    }
}

You will notice that I have two implementations. That is on purpose. The whole point of using interfaces is to gain the flexibility of being able to change implementations to prove the decoupling facility provided by DI.

Don’t forget to do some Unit Testing in an xUnit project, whilst you are at it.

Step Two — Inject It

Now, the next step is to inject your interface, along with the implementation. This should happen when your app builds.

This is .Net 6. So, we do this in Program.cs. I am using Scoped way of injecting. There are other ways to inject, which are beyond my knowledge level.

//Ideally, you want to use one of the two implementation.
//Ultimatley, the goal here, of Dependency Injection,
//is the flexibility to change the implementation class
//without affecting the code within.
//use the first implementation
//builder.Services.AddScoped<ISayMyName,SayMyNameOne>();
//use the second implementation
builder.Services.AddScoped<ISayMyName, SayMyNameTwo>();

Hopefully, you will read the comments.

Essentially, I, the developer, the coder, and also you, can ‘switch’ between the two implementations.

This way, you use the implementation you want, and the code, is completely unaware of it, hence, decoupling itself from the implementations, current, past and future.

Step Three — The Constructor! Don’t Forget This

The key step.

Note the assignment that happens in the constructor. Without that, DI would fail.

[Route("api/[controller]")]
[ApiController]
public class NameWithDIController : ControllerBase
{
    ISayMyName _sayMyName;

    //this is the key part
    //this is where, the interface is married to the implementation class
    //as provided by the startup settings in Program.cs
    public NameWithDIController(ISayMyName sayMyName)
    {
        _sayMyName = sayMyName;
    }

    [HttpGet]
    [Route("SayMyName")]
    public ActionResult<string> GetName()
    {          
        var response = _sayMyName.IAmName();

        return response;
    }
}

Final Note

Of course, this is the most simplest case of doing DI. It may not even be the most efficient way of doing it.

But, it works. Hope it helps you.

Similar
Apr 16, 2022
Author: Matthew MacDonald
Sometimes it’s the little things that count.When .NET 6 dropped this November, a few top-line items grabbed all the attention. I’m talking about C# 10, hot reload, Blazor’s AOT compilation, and some serious inner loop performance improvements. All of them...
Aug 23, 2022
Author: Luis Rodrigues
Suppose we are building a web api that contains a route to send notification messages to other systems.For security matters, before sending any notification message, we need to provide some credentials to these systems to they accept our messages.However, these...
Nov 22, 2021
Author: MBARK T3STO
Dispose and Finalize are two methods you often use to release resources occupied by your .NET and .NET Core applications running in the context of the CLR. Most importantly, if you have unmanaged resources in your application, you should release...
Aug 26, 2022
Author: Jaydeep Patil
We are going to discuss the RabbitMQ Message Queue and its implementation using .NET Core 6 API as Message Producer and Console Application as a Message Consumer.Agenda Introduction of RabbitMQ Benefits of using RabbitMQ...
Send message
Email
Your name
*Message


© 1999–2023 WebDynamics
1980–... Sergey Drozdov
Area of interests: .NET | .NET Core | C# | ASP.NET | Windows Forms | WPF | Windows Phone | HTML5 | CSS3 | jQuery | AJAX | MS SQL Server | Transact-SQL | ADO.NET | Entity Framework | IIS | OOP | OOA | OOD | WCF | WPF | MSMQ | MVC | MVP | MVVM | Design Patterns | Enterprise Architecture | Scrum | Kanban