What is ASP.NET Core?

ASP.NET Core is a free, open-source, cross-platform framework for building modern, cloud-based, internet-connected applications. It's a high-performance, modular, and extensible framework that allows you to build:

• Web applications
• IoT applications
• Mobile backends

ASP.NET Core combines the MVC (Model-View-Controller) and Web API frameworks into a single, powerful programming model. It's designed for performance and provides a flexible architecture that can be hosted on-premises or in the cloud.

Getting Started

To begin your journey with ASP.NET Core, you'll need to set up your development environment. This typically involves installing:

• .NET SDK (Software Development Kit)
• A code editor or IDE (like Visual Studio, VS Code, or JetBrains Rider)

Let's create your first ASP.NET Core application:

dotnet new webapp -o MyWebApp
cd MyWebApp
dotnet run
                    

This command creates a new Razor Pages web application and runs it. You'll see a basic web page appear in your browser.

ASP.NET Core MVC Basics

Model-View-Controller (MVC) is a design pattern that structures an application into three interconnected components:

• Model: Represents the data and business logic.
• View: Renders the user interface.
• Controller: Handles user input, interacts with the Model, and selects the View to render.

We'll dive deeper into creating MVC applications, routing, and managing views in subsequent tutorials.

// Example Controller Snippet
public class HomeController : Controller
{
    public IActionResult Index()
    {
        return View();
    }
}
                    

Razor Pages Fundamentals

Razor Pages provides a page-centric approach to building ASP.NET Core web UIs. It simplifies the development of page-based applications by bringing together handlers and the UI into a single unit.

Each Razor Page consists of a Razor file (.cshtml) and a corresponding PageModel class (.cshtml.cs).

// Example Razor Page (Index.cshtml.cs)
public class IndexModel : PageModel
{
    public string Message { get; set; }

    public void OnGet()
    {
        Message = "Welcome to Razor Pages!";
    }
}
                    

// Example Razor Page (Index.cshtml)
@page
@model IndexModel
@{
    ViewData["Title"] = "Home page";
}

@Model.Message