Introduction to ASP.NET Core

Lesson 7: Introduction to ASP.NET Core

In this lesson, you will learn about ASP.NET Core, the modern framework for building web applications and APIs.

---

🌐 What is ASP.NET Core?

ASP.NET Core is an open-source, cross-platform framework for building:

• Web applications (MVC and Razor Pages).
• RESTful APIs.
• Real-time apps (SignalR).

It runs on Windows, Linux, and macOS.

---

🚀 Key Features

ASP.NET Core provides:

• Cross-platform support: Run anywhere.
• High performance: Optimized for speed and scalability.
• Dependency Injection: Built-in DI container.
• Unified development model: For web UI and APIs.
• Modern hosting: Integrated with Kestrel server.

---

🛠️ Project Structure

An ASP.NET Core project typically includes:

• Program.cs: Entry point for configuring the app.
• Startup.cs: (in older versions) Configures services and middleware.
• appsettings.json: Configuration file.
• Controllers: API or MVC controllers.
• Views: Razor pages or views.

---

⚙️ Minimal Hosting Model

.NET 6 and later use a minimal hosting model. Example:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers();

var app = builder.Build();

app.MapControllers();

app.Run();

---

🌟 Middleware Pipeline

Middleware are components that process HTTP requests and responses. Example pipeline:

app.UseRouting();

app.UseAuthentication();
app.UseAuthorization();

app.MapControllers();

---

💡 Example Controller

Here is a simple API controller:

using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("api/[controller]")]
public class HelloController : ControllerBase
{
    [HttpGet]
    public string Get()
    {
        return "Hello, ASP.NET Core!";
    }
}

---

📈 Performance

ASP.NET Core is one of the fastest web frameworks available, thanks to:

• Kestrel web server.
• Asynchronous programming model.
• Optimized libraries.

---

📝 Summary

ASP.NET Core is the preferred framework for building high-performance web apps and APIs in .NET.

---

✅ Next Lesson

Lesson 8: Entity Framework Core Basics