Introduction to ASP.NET Core

What is ASP.NET Core?

ASP.NET Core is a free, open-source, cross-platform framework for building modern, cloud-enabled, internet-connected applications. It is a rewrite of the ASP.NET platform, offering significant performance improvements, a more modular architecture, and support for multiple development environments. ASP.NET Core can be used to build web applications, IoT devices, and mobile backends.

Key Features and Benefits

• High Performance: Designed from the ground up for speed and efficiency.
• Cross-Platform: Runs on Windows, macOS, and Linux.
• Open Source: Developed in the open with community contributions.
• Unified Framework: Combines the capabilities of ASP.NET MVC and Web API.
• Modern Development: Supports dependency injection, asynchronous programming, and cloud-native architectures.
• Flexible Hosting: Can be self-hosted or hosted on IIS, Nginx, Apache, or Docker.

Setting Up Your Development Environment

To start building with ASP.NET Core, you'll need the following:

1. .NET SDK: Download and install the latest .NET SDK from the official .NET website. This includes the .NET runtime and development tools.

   Download .NET SDK

2. Code Editor:
   • Visual Studio: A powerful IDE for Windows and macOS.
   • Visual Studio Code: A lightweight, cross-platform code editor with excellent C# and .NET support via extensions.
   • JetBrains Rider: A cross-platform .NET IDE.

Creating Your First ASP.NET Core Application

You can create a new ASP.NET Core web application using the .NET CLI. Open your terminal or command prompt, navigate to the directory where you want to create your project, and run the following command:

dotnet new webapp -o MyWebApp
cd MyWebApp
dotnet run

This command will:

• Create a new directory named MyWebApp.
• Generate the basic files for a Razor Pages web application.
• Navigate into the new directory.
• Start the Kestrel web server, making your application accessible at a local URL (usually https://localhost:5001 or http://localhost:5000).

Open your web browser and navigate to the provided URL to see your first ASP.NET Core application running!

Understanding the Project Structure

A typical ASP.NET Core web application project has the following structure:

• Pages/: Contains Razor Pages (.cshtml files for UI and .cshtml.cs files for code-behind).
• wwwroot/: Contains static files like HTML, CSS, JavaScript, and images.
• appsettings.json: Configuration settings for your application.
• Program.cs: The entry point of your application, where the web host is configured.
• Startup.cs (in older versions, now part of Program.cs): Configures the application's request pipeline.